were not adequate to accurately monitor low PM concentrations.
Commenters further contended that PM CPMS are essentially the same
thing as PM CEMS, and that there were no clear instructions on how to
``certify'' PM CPMS, as was required in the proposed rule. Commenters
added that they do not understand how the recording of hourly and 30-
day rolling averages of the output from these monitors will be useful
to demonstrate

performance or evaluate compliance with a PM limit. One commenter
suggested that the EPA remove the PM CPMS requirements altogether for
all industrial boilers.
    Response: We are revising the PM CEMS requirements in the final
rule as explained above.
    In responding to this comment specifically, we believe it is useful
to review the procedures and acceptance criteria of PS-11, the protocol
mandated by the 2011 final CISWI rule.
Performance Specification-11
    PS-11 is structured differently than other PSs that apply to
validating the performance of gaseous pollutant CEMS. This is primarily
because the pollutant, PM, is defined entirely by the test method
specified by regulation to measure it. As the industry commenters note,
there are no independent standard reference materials for PM
concentrations as there are for gaseous pollutants (e.g., NIST
traceable compressed gases for validating SO2 or
NOX instrumental measurements). The only reference standard
for determining the PM concentration in an air or stack gas sample is
the reference test method. In the case of the CISWI final rule, the
rule specifies EPA Method 5 for measuring filterable PM concentration
(e.g., in mg/dscm).
    Performance Specification 11 provides procedures and acceptance
criteria for validating the performance of several types of PM CEMS
technologies. Although there are multiple instrument and data reporting
operational performance checks in PS-11 that are similar in concept to
those for gaseous pollutant CEMS, there is a principal PM CEMS
performance requirement that is distinctly different. That difference
is the development of a site-specific PM CEMS correlation or
mathematical response curve. There are two key procedural elements to
developing that correlation. First, PS-11 requires that the source
conduct stack test runs using an EPA PM test method (e.g., Method 5)
and simultaneously collect corresponding PM CEMS output data. Second,
the source must vary the operation of the control device manually in
order to produce a range of PM concentrations. Performance
Specification 11, section 8.6, requires at least five test runs at each
of three different operating conditions (i.e., low, mid and high PM
concentrations) for a total of 15 or more test runs that range from 25
to 100 percent of allowable emissions. Then the source must use the
test method data and the corresponding PM CEMS output data to develop
an equation (i.e., a calculated linear or nonlinear curve) that will be
used to define the relationship between the PM CEMS output and the test
method measured PM concentrations. Each site-specific correlation must
meet several PS-11 acceptance criteria including limits on confidence
interval and tolerance interval equating to 25 percent of
the applicable emissions limit.
Discussion of Technical Issues
    In prior comments submitted to the EPA on the PM CEMS requirements
for waste-burning kilns, one issue raised about conducting the testing
to meet the PS-11 correlation development requirement is the
impracticality of varying the emissions from a FF control device. Many
CISWI units subject to the standards use FF control devices.
    We agree with commenters that there are typically few, if any,
physical adjustments one can apply to a FF or to the waste-burning kiln
process to change the outlet PM concentration significantly. A FF
produces essentially a constant outlet concentration even with changes
to the inlet loading or flow (http://www.epa.gov/ttnchie1/mkb/documents/ff-pulse.pdf). Although PS-11 allows some flexibility when
control device perturbations are not possible, the resulting
correlation would apply for only the narrow range of concentrations
measured during the testing. The result would be that the PM CEMS would
be correlated only for a relatively small range of conditions below the
applicable compliance limit. This range would not necessarily include
situations where the standard might be exceeded. Without the ability to
calculate emissions should the FF performance change from initial test
conditions (e.g., bag leaks begin to develop), such a limited
correlation range would render the PM CEMS less reliable for
calculating long term average concentrations or emissions rates and for
verifying compliance. Additionally, it is difficult and resource
intensive to modify baghouse control efficiency in a way that is
representative of normal operations at a waste-burning kiln.
    Commenters also cited problems in developing correlations in stack
gases with variable PM constituents and physical characteristics when
using light scatter or scintillation detection PM CEMS devices. As
noted above and in the EPA's technology background documents (e.g.,
http://www.epa.gov/ttn/emc/cem/pmcemsknowfinalrep.pdf and http://www.epa.gov/ttn/emc/cem/r4703-02-07.pdf), the correlations developed
for these types of instruments are inherently dependent on the particle
structure, size and other physical characteristics as well as PM mass
in the exhaust gases for each site. Put another way, these light-based
PM CEMS produce a signal that can vary when different fuels or raw
materials are introduced to the kilns or ERU even when the FF outlet
mass concentration remains unchanged.
    To the extent that physical characteristics of the PM in the stack
remain stable, correlations for light-based PM CEMS meeting PS-11
performance criteria can represent mass rates to the degree of accuracy
required by PS-11. For example, there are various design structures
used in some light-based PM CEMS devices that can mitigate the effects
of changes in the physical aspects of particles on measurement
uncertainty. In addition to the type of light effect measured (e.g.,
Rayleigh or Mie scattering or light scintillation), the detector
wavelength and the frequency are design factors that will affect how
the PM CEMS responds to small changes in the physical appearance of the
PM.
    On this point, we note that if a source owner were concerned about
the ability of a light-based PM CEMS to meet the requirements of PS-11
because of variable physical characteristics of particles in the stack,
there is at least one other PM CEMS technology based more directly on
mass measurement rather than on light scatter or light scintillation
characteristics. The currently available Beta gauge technology does not
suffer from this particular technical problem. The Beta attenuation PM
CEMS, also called Beta gauge, extracts a sample for the stack gas and
collects the PM on a filter tape. The device periodically advances the
tape from the sampling mode to an area where the sample is exposed to
Beta radiation. The detector measures the amount of Beta emitted by the
sample and that amount can be directly related to the mass of PM on the
filter. The Beta gauge sensitivity or detection limit can be enhanced
(i.e., lowered) with greater sample volumes produced from sampling
intervals up to an hour or longer.
    Another PM mass detector projected for greater use as PM CEMS is
the TEOM. Often used in measuring ambient levels of PM, the TEOM
operates on a basic principle that can be made traceable to NIST
laboratory standards. The TEOM can provide a continuous measure of PM
mass in a sample extracted from the stack and routed to the detector.
Tapered element oscillating microbalance based PM CEMS are not yet
commercially available.

    Commenters identified another factor contributing to the difficulty
of meeting PS-11 correlation requirements for low PM concentrations
corresponding to a low applicable emissions limit, as with the
promulgated PM standards here for waste-burning kilns and biomass ERUs.
We have recently reevaluated the capabilities of the EPA Method 5 for
measuring low concentrations of PM (See the memo ``Revision of
Estimated Method 5 Detection Limit'' in the CISWI docket) and have
determined a Method 5 method detection limit of approximately 2 mg/dscm
for a 1-hour test run. The uncertainty of a measurement with Method 5
at this PM concentration would be from 50 to 100 percent (i.e., 1 to 2 mg/dscm). We can determine a PQL using ~3 x method
detection limit to reduce that Method 5 measurement uncertainty to
10 to 20 percent. That means that the PQL for a 1-hour test
run with Method 5 would be approximately 6 mg/dscm 0.6 to
1.2 mg/dscm.
    The CISWI PM emissions limit for existing waste-burning kiln
sources is 3.6 mg/dscm, and is 11 mg/dscm for biomass ERUs. The new
source limits are the same for waste-burning kilns but are 5.1 mg/dscm
for biomass ERUs. As noted above, PS-11 specifies acceptable criteria
for a correlation directly related to the applicable emissions limit.
For a PM CEMS set up to measure compliance with a 3.6 mg/dscm limit,
the inherent uncertainty associated with a 1-hour Method 5 measurement
(0.6 to 1.2 mg/dscm) would constitute more than half of the
25 percent of the applicable PS-11 acceptance threshold
(i.e., 0.9 mg/dscm) of the mid-level PS-11 correlation test
(i.e., the correlation for the middle of the three PS-11 correlation
points). Factoring in the inherent PM CEMS response variability and the
uncertainty associated with the representative sampling (e.g., PM and
flow stratification), we agree with commenters that trying to satisfy
PS-11 at such low concentrations using 1-hour Method 5 test runs would
be problematic. This drawback applies regardless of the type of PM CEMS
technology used.
    As commenters to the Portland Cement NESHAP have noted, one can
improve the method detection capabilities of the Method 5 or other
filterable PM test method by increasing sampling volume and run time.
For example, a test run time of about 2 hours will improve the Method 5
PQL to about 3 mg/dscm. The measurement uncertainty associated with a
2-hour test run at 3 mg/dscm would be about 0.3 to 0.6 mg/
dscm. At this level, the uncertainty associated with the PM test method
measurements alone would be about half of the correlation limit allowed
in PS-11. To achieve a PQL of 1 mg/dscm and a measurement uncertainty
of about 0.01 to 0.2 mg/dscm, one would need to conduct a
test run of 6 hours or longer. As noted above, the PS-11 correlation
calculations would also have to account for any PM CEMS analytical and
measurement variability.
    Using data from longer Method 5 test runs will improve the
probability of a PM CEMS meeting PS-11 correlation requirements but, as
commenters note, will also raise practicality concerns without
completely resolving the issue. For example, the time to complete 15 1-
hour test runs under three different emissions conditions may be 3 to 6
days of field work, while the time to complete 15 6-hour test runs
under three different emissions conditions will require at least 2
weeks of field work in order to produce and maintain the operating
conditions associated with three different emissions rates. Longer test
runs lower the variability of Method 5 PM measurements at near
detection limit levels from  50 percent to below  25 percent; however, the variability of Method 5 results at
these low levels represents a significantly larger portion of the
 25 percent correlation requirement of PS-11 than would
Method 5 data collected at higher PM concentrations. Method 5
measurement uncertainty becomes increasingly greater with lowering PM
concentration and thus reference measurement variability hinders the
PS-11 correlation process the most for the best performing sources.
Thus, the ultimate result might still lack certainty and would also
pose the most difficulty and uncertainty to those sources with lower PM
concentrations (potentially disadvantaging more efficient operators).
    Although longer Method 5 test runs and longer beta gauge sampling
times reduce difficulties with PS-11 correlation for a PM CEMS, the EPA
believes that this correlation will not be technically achievable for a
significant number of waste-burning kiln and biomass ERU sources, a
result in part due to the Method 5 PM emissions measurement variability
at the low concentrations necessary to maintain compliance with the
standard. The PM CEMS correlations then become approximations more
qualitative than quantitative with high levels of uncertainty at low
concentrations (i.e., the correlations do not meet PS-11 requirements).
This characteristic exists regardless of the type of PM CEMS technology
used by the source since it involves variability not only of the PM
CEMS but also the Method 5 test data, variability of raw material and
additive feeds to the waste-burning kiln, and the changing particle
sizes, shapes, and density with process operations (e.g., mill on
versus mill off, type of fuel being used in the ERU).
    Making PM CEMS work at low concentrations (<10 mg/dscm) at waste-
burning kiln and biomass ERU sources is not impossible; although, to
expect that correlations would be achievable at all low emissions
sources would be unrealistic. Additionally, the technical limitations
do not mean that PM CEMS cannot be used to monitor for compliance. A PM
CEMS that does not meet the EPA correlation requirements can still
produce data indicative of trends and changes in emissions control.
Particulate Matter CEMS technology can be effective in monitoring
control device performance (see, e.g., 77 FR 9371 (February 16, 2012))
where the EPA established PM CPMS parametric operating limits for
electric utility steam generating units.
A Monitoring Approach Alternative to PM CEMS and PS-11
    To address technical issues associated with PM CEMS meeting PS-11
correlation requirements at low PM emissions concentrations from waste-
burning kilns and biomass ERUs, the impracticability in perturbing FF
emission rates to establish PS 11 correlation curves, and the
potentially variable PM emissions characteristics expected from waste-
burning kilns, the EPA is finalizing the change of the compliance basis
for the PM emissions limit from PM CEMS. For monitoring continuous
compliance, the rule requires PM CEMS equipment but, as explained
below, that equipment would be used for continuous parametric
monitoring rather than for direct measure of compliance with the
numerical PM emissions limit.
    Specifically, this final rule recognizes the value of PM monitoring
technology sensitive to changes in PM emissions concentrations and use
of such a tool to assure continued good operation of PM control
equipment. This approach avoids the PM CEMS calibration (i.e., PS-11
correlation). Therefore, the EPA is including provisions that a site-
specific parametric operating limit be established during the
performance test, that there be continuous monitoring of that
parametric limit using a PM CPMS, that an exceedance of that site-
specific operating limit be reported as a deviation and trigger
immediate corrective action and a Method 5 performance test within 45
days.

    In the May 2012 Proposed National Emission Standards for Hazardous
Air Pollutants for the Portland Cement Manufacturing Industry and
Standards of Performance for Portland Cement Plants The EPA proposed
the use of PM CPMS for continuous monitoring of PM emissions as a 30-
day rolling average established by identifying the average PM CPMS
response corresponding to the highest 1-hour PM compliance test.
Failure to meet this 30-day rolling average would result in retesting.
Industry commented that this requirement would trigger unnecessary
retests for many facilities, especially for cleaner sources. This is a
legitimate issue. To avoid a perverse result, the EPA is modifying the
way PM CPMS operating limits are established. Sources whose compliance
with the PM emission standard are shown to be 75 percent or below the
emission limit in the PM method 5 compliance test will set their PM
parametric operating limit to be a 30-day rolling average equivalent to
that 75 percent level. Sources whose compliance with the PM emission
standard are above 75 percent of the emission limit will establish
their operating limit as a 30-day rolling average equal to the average
PM CPMS values recorded during the PM compliance test. It should be
noted that this provision does not affect the actual emission limit
that must be met.

F. What other actions are we taking?

    In this final action, we are denying requests for reconsideration
on all issues contained in the petitioners' requests for
reconsideration that we did not include in the December 23, 2011,
proposed rule. The issues for which we are denying reconsideration
failed to meet the standard for reconsideration under CAA section
307(d)(7)(B) and we determined that reconsideration was not otherwise
appropriate. Specifically, on these issues, the petitioner has failed
to show the following: That it was impracticable to raise their
objections during the comment period; or that the grounds for their
objections arose after the close of the comment period; and/or that
their concern is of central relevance to the outcome of the rules. We
have concluded that no clarifications to the underlying rules are
warranted for the 19 remaining petitioners' issues for the reasons set
forth in the memorandum titled ``Denied CISWI Petition Issues'' found
in the CISWI docket. The following issues are addressed in that
memorandum.
     Work practice standards should be used for startup/
shutdowns and malfunctions.
     Exempt or revise limits for units combusting de minimis
amounts of waste.
     Clarify applicability of CISWI standards to marine vessel
units or units located on the outer continental shelf.
     Clarify applicability to temporary or portable units.
     Reduce performance testing requirements to be more
consistent with requirements of other rules.
     Reconsider elimination of provisions that allow missing
CEMS data.
     Do not include emissions data for combination boiler
units.
     CISWI does not satisfy CAA 112(c)(6) requirements for POM
and PCB.
     MACT floor statistical approach concerns.
     MACT floor must reflect the average, the UPL is not the
same as the average emission level.
     MACT floor pollutant-by-pollutant approach concerns.
     Non-detect methodology is unlawful.
     Beyond-the-floor analysis is unlawful and arbitrary.
     Compliance cost and wildlife concerns for small remote
incinerators.
     ``Refinery gas'' definition should be included in the
CISWI rule.
     Clarify that construction and demolition wood is not a
solid waste.

G. What are the impacts associated with the amendments?

1. What are the primary air impacts?
    We have estimated the potential emissions reductions from existing
sources that may be achieved through implementation of the emission
limits. However, we realize that some CISWI owners and operators are
likely to determine that alternatives to waste incineration are viable,
such as further waste segregation or sending the waste to a landfill or
MWC, if available. In fact, sources operating incinerators, where
energy recovery is not a goal, may find it cost effective to
discontinue use of their CISWI unit altogether. Therefore, we have
estimated emissions reductions attributable to existing sources
complying with the limits, as well as those reductions that would occur
if the facilities with incinerators and small, remote incinerators
decide to discontinue the use of their CISWI unit and use alternative
waste disposal options.
    For units combusting wastes for energy production, such as ERUs and
waste-burning kilns, the decision to combust or not to combust waste
will depend on several factors. One factor is the cost to replace the
energy provided by the waste material with a traditional fuel, such as
natural gas. Another factor would be whether the owner or operator is
purchasing the waste or obtaining it at no cost from other generators,
or if they are generating the waste on-site and will have to dispose of
the materials in another fashion, such as landfills. Lastly, these
units would have to compare the control requirements needed to meet the
CISWI emission limits with those needed if they stop burning solid
waste and are then subject to a NESHAP instead. As mentioned before, we
have attempted to align the monitoring requirements for similar non-
waste-burning sources as closely as possible in an effort to make them
consistent and to help sources make the cross-walk between waste and
non-waste regulatory requirements as simple as possible.
    The emissions reductions that would be achieved under this final
rule using the definition of solid waste under RCRA and the proposed
CISWI emission limits are presented in Table 5 of this preamble.

 Table 5--Emissions Reductions for MACT Compliance and Alternative Disposal Options for Existing CISWI Using the
                                                 Emission Limits
----------------------------------------------------------------------------------------------------------------
                                                                                Reductions achieved
                                                                                assuming incinerators
                                                                    Reductions achieved      and small, remote
                            Pollutant                              through meeting MACT      incinerators use
                                                                         (ton/yr)          alternative disposal
                                                                                (ton/yr) \a\
----------------------------------------------------------------------------------------------------------------
HCl.............................................................              772.2                   784.3
CO..............................................................           20,093                  20,058
Pb..............................................................                2.5                     2.71

Cd..............................................................                1.807                   1.809
Hg..............................................................                0.341                   0.344
PM (filterable).................................................            2,397                   2,401
dioxin, furans..................................................                0.000062                0.000064
NOX.............................................................            5,292                   5,399
SO2.............................................................            6,211                   6,262
                                                                 -----------------------------------------------
    Total.......................................................           34,771                  34,909
----------------------------------------------------------------------------------------------------------------
\a\ The estimated emission reduction does not account for any secondary impacts associated with alternate
  disposal of diverted ERU fuel.

    The EPA expects that many existing CISWI owners and operators may
find that alternate disposal options are preferable to complying with
the standards for the incinerator and small, remote incinerator
subcategories. Our experience with regulations for MWC, HMIWI and, in
fact, CISWI, has shown that negative growth in the source category
historically occurs upon implementation of CAA section 129 standards.
Since CISWI rules were promulgated in 2000 and have been in effect for
existing sources since 2005, many existing units have closed. At
promulgation in 2000, the EPA estimated 122 units in the CISWI
population. In comparison, the incinerator subcategory in this rule,
which contains any such units subject to the 2000 CISWI rule, has 27
units. The EPA is not aware of any construction of new units since 2000
so we do not believe there are any units that are currently subject to
the 2000 CISWI NSPS. The revised CISWI rule is more stringent so we
expect this trend to continue. However, the EPA does recognize that
some facilities may opt to replace aging incinerator units with new
units where it is cost effective or alternative disposal options are
not feasible, as may be the case with some incinerators, or in very
remote locations. We estimate that there could be one new incineration
unit within the next 5 years following this final rule, and possibly
five new small remote incinerators within that time. In these cases, we
have developed model CISWI unit emissions reduction estimates for these
subcategories using the current existing unit baseline, based on
average emission concentration values and sizes from our current
inventory and the new source emission limits. Table 6 of this preamble
presents the model plant emissions reductions that are expected for new
sources.

                              Table 6--Emissions Reductions on a Model Plant Basis
----------------------------------------------------------------------------------------------------------------
                                                                  Emission reduction for CISWI subcategory model
                                                                        units (tpy unless otherwise noted)
                            Pollutant                            -----------------------------------------------
                                                                                Small, remote
                                                                        Incinerator             incinerator
----------------------------------------------------------------------------------------------------------------
HCl.............................................................                  2.62                   0.0
CO..............................................................                  0.0                    0.25
Pb..............................................................                  0.55                   0.11
Cd..............................................................                  0.15                   0.019
Hg..............................................................                  0.0026                 0.00036
PM (filterable).................................................                103                     10.7
D/F (total mass) \a\............................................                  0.0011                 0.0
NOX.............................................................                 11.3                    0.0
SO2.............................................................                  5.1                    4.5
    Total.......................................................                122                     22.0
----------------------------------------------------------------------------------------------------------------
\a\ D/F estimates are given in lb/yr.

    We do not anticipate that any new energy recovery or waste-burning
kiln units will be constructed and will instead use alternative waste
disposal methods or alternative fuels that will not subject them to the
CISWI rule. For example, whole tires obtained from approved tire
management programs and tire-derived fuel from which the metal has been
removed is not considered solid waste under the definition of solid
waste. Consequently, new cement kiln owners will assess their
regulatory requirements under CISWI for burning whole tires or tire-
derived fuel that does not have metals removed against the costs
associated with removing the metal or obtaining tires from an approved
source and complying with the applicable NESHAP instead of the CISWI
rule. Our research suggests that metal removal is routinely practiced
and that several state waste tire management programs are already in
place and would most likely be a viable option for new kiln owners so
that they would not be subject to the CISWI regulations. Indeed, we
expect that all existing cement kilns that are classified as being
waste-burning solely due to whole tires will, by the effective date for
the CISWI standards, find a way to obtain their tires through an
approved

tire management plan. Likewise, new sources could engineer their
process to minimize waste generation in the first place or to separate
wastes so that the materials sent to a combustion unit would not meet
the definition of solid waste to begin with. For waste that is
generated, our cost analyses have found that alternative waste disposal
is generally available and less expensive.
2. What are the water and solid waste impacts?
    In our analysis, we have selected the lowest cost alternative
(i.e., compliance or alternative disposal) for each facility. We
anticipate affected sources will need to apply additional controls to
meet the emission limits. These controls may use water, such as wet
scrubbers, which would need to be treated. We estimate an annual
requirement of 71 billion gallons per year of additional water would be
required as a result of operating additional controls or increased
sorbent use.
    Likewise, the addition of PM controls or improvements to controls
already in place will increase the amount of particulate collected that
will require disposal. Furthermore, ACI may be used by some sources,
which will result in additional solid waste needing disposal. The
annual amounts of solid waste that would require disposal are
anticipated to be approximately 25,400 tpy from PM capture and 13,700
tpy from ACI.
    Perhaps the largest impact on solid waste would come from owners
and operators who decide to discontinue the use of their CISWI unit and
instead send waste to the landfill or MWC for disposal. Based on
tipping fees and availability, we would expect most, if not all, of
this diverted waste to be sent to a local landfill. As we discuss
above, it may be that a good portion of the incinerators would
determine that alternative disposal is a better choice than compliance
with the standards. We estimate that approximately 110,600 tpy of waste
would be diverted to a landfill.
    For new CISWI units, we estimate an annual requirement of 980,000
gallons per year of additional water would be required as a result of
operating additional controls. The annual amounts of solid waste that
would require disposal are anticipated to be approximately 6.8 tpy from
PM capture and 4.7 tpy from ACI.
3. What are the energy impacts?
    The energy impacts associated with meeting the emission limits
would consist primarily of additional electricity needs to run added or
improved air pollution control devices. For example, increased scrubber
pump horsepower may cause slight increases in electricity consumption
and sorbent injection controls would likewise require electricity to
power pumps and motors. In our analysis, we have selected the lowest
cost alternative (i.e., compliance or alternative disposal) for each
facility. By our estimate, we anticipate that an additional 217,400 MW-
hours per year would be required for the additional and improved
control devices.
    As discussed earlier, there could be instances where owners and
operators of ERUs and waste-burning kilns decide to cease burning waste
materials. In these cases, the energy provided by the burning of waste
would need to be replaced with a traditional fuel, such as natural gas.
Assuming an estimate that 50 percent of the energy input to ERUs and
kilns are from waste materials, an estimate of the energy that would be
replaced with a traditional fuel if all existing units stopped burning
waste materials, is approximately 56 TBtu/yr.
    For new CISWI units, we anticipate that 94 MW-hours per year would
be required for additional and improved control devices. Since we do
not anticipate any new energy recovery or waste-burning kiln units to
be constructed, there would be no additional estimate for energy that
would be replaced with a traditional fuel.
4. What are the secondary air impacts?
    For CISWI units adding controls to meet the emission limits, we
anticipate minor secondary air impacts. The combustion of fuel needed
to generate additional electricity and to operate RTO controls would
yield slight increases in emissions, including NOX, CO, PM
and SO2 and an increase in CO2 emissions. Since
NOX and SO2 are covered by capped emissions
trading programs, and methodological limitations prevent us from
quantifying the change in CO and PM, we do not estimate an increase in
secondary air impacts for this rule from additional electricity demand.
    We believe it likely that the incinerators may elect to discontinue
the use of their CISWI unit and send the waste to the landfill or other
disposal means. As we discussed in the solid waste impacts above, this
could result in approximately 110,600 tpy of waste going to landfills.
By using the EPA's Landfill Gas Estimation Model, we estimate that,
over the 20-year expected life of a CISWI unit, the resulting methane
generated by a landfill receiving the waste would be about 96,400 tons.
If this landfill gas were combusted in a flare, assuming typical flare
emission factors and landfill gas chlorine, Hg and sulfur
concentrations, the following emissions would be expected: 20 tons of
PM; 8 tons of HCl; 16 tons of SO2; 890 tons of CO; 46 tons
of NOX; and 1.4 lbs of Hg.
    Similar to existing units, we anticipate minor secondary air
impacts for new CISWI units adding controls as discussed above.
5. What are the cost and economic impacts?
    We have estimated compliance costs for all existing units to add
the necessary controls and monitoring equipment, and to implement the
inspections, recordkeeping and reporting requirements to comply with
the final CISWI standards. We have also analyzed the costs of
alternative disposal for the subcategories that may have alternative
options to burning waste, specifically for the incinerators and the
small, remote incinerators that may have an alternative to
incineration. In our analysis, we have selected the lowest cost
alternative (i.e., compliance or alternative disposal) for each
facility. Based on this analysis, we anticipate an overall total
capital investment of $816 million with an associated total annual cost
of $271 million ($2008). For comparison, the 2011 final rule, estimated
an overall total capital investment of $652 million with an associated
total annual cost of $232 million ($2008). The annualized cost of
today's final rule are approximately 17% higher than those of the final
2011 CISWI rule. The changes in cost result from revising the
inventories of the ERUs, waste-burning kilns, and small remote
incinerators as discussed in Section II.C. of this preamble: ``Summary
of Significant Changes Since Proposal.''
    Under the rule, the EPA's economic model suggests the average
national market-level variables (prices, production-levels,
consumption, international trade) will not change significantly (e.g.,
are less than 0.001 percent).
    The EPA performed a screening analysis for impacts on small
entities by comparing compliance costs to sales/revenues (e.g., sales
and revenue tests). The EPA's analysis found the tests were below 3
percent for four of the five small entities included in the screening
analysis.
    In addition to estimating this rule's social costs and benefits,
the EPA has estimated the employment impacts of the final rule. We
expect that the rule's direct impact on employment will be small. For
the reconsideration final, the estimated employment changes range

between -400 to +900 employees, with a central estimate of +200.
    We have not quantified the rule's indirect or induced impacts. For
further explanation and discussion of our analysis, see the
introductory memo and Section 3 of the RIA.
    For new CISWI units, we have estimated compliance costs for units
coming online in the next 5 years. This analysis is based on the
assumption that one new incinerator will come online over 5 years and
that three new small remote incinerators will come online in the next
year, followed by one new small remote incinerator per year for
subsequent years. Additionally, it was assumed that each model unit
will add the necessary controls, monitoring equipment, inspections,
recordkeeping and reporting requirements to comply with NSPS limits.
Based on our analysis, we anticipate an overall total capital
investment of $9.3 million over 5 years with an associated total annual
cost (for 2015) of $2.7 million.
6. What are the benefits?
    We estimate the monetized benefits of this regulatory action to be
$420 million to $1.0 billion (2008$), 3 percent (discount rate) in the
implementation year (2015). The monetized benefits of the regulatory
action at a 7 percent discount rate are $380 million to $930 million
(2008$). Using alternate relationships between PM2.5 and
premature mortality supplied by experts, higher and lower benefits
estimates are plausible but most of the expert-based estimates fall
between these two estimates.\10\ Since the reconsideration proposal, we
have made several updates to the approach we use to estimate mortality
and morbidity benefits in the PM NAAQS RIAs (U.S. EPA, 2012a,b)
11 12, including updated epidemiology studies, health
endpoints, and population data. Although we have not re-estimated the
benefits for this rule to apply this new approach, these updates
generally offset each other, and we anticipate that the rounded
benefits estimated for this rule are unlikely to be different than
those provided below. More information on these updates can be found in
the PM NAAQS RIAs .A summary of the monetized benefits estimates at
discount rates of 3 percent and 7 percent is in Table 7 of this
preamble.
---------------------------------------------------------------------------

    \10\ Roman, et al., 2008. Expert Judgment Assessment of the
Mortality Impact of Changes in Ambient Fine Particulate Matter in
the U.S. Environ. Sci. Technol., 42, 7, 2268-2274.
    \11\ U.S. Environmental Protection Agency (U.S. EPA). 2012a.
Regulatory Impact Analysis for the Proposed Revisions to the
National Ambient Air Quality Standards for Particulate Matter. EPA-
452/R-12-003. Office of Air Quality Planning and Standards, Health
and Environmental Impacts Division. June. Available at http://www.epa.gov/ttnecas1/regdata/RIAs/PMRIACombinedFile_Bookmarked.pdf.
    \12\ U.S. Environmental Protection Agency (U.S. EPA). 2012b.
Regulatory Impact Analysis for the Final Revisions to the National
Ambient Air Quality Standards for Particulate Matter. EPA-452/R-12-
003. Office of Air Quality Planning and Standards, Health and
Environmental Impacts Division. December. Available at http://www.epa.gov/pm/2012/finalria.pdf.

             Table 7--Summary of the Monetized Benefits Estimates for the CISWI NSPS and EG in 2015
                                             [Millions of 2008$] a b
----------------------------------------------------------------------------------------------------------------
                                   Estimated emission     Total monetized benefits     Total monetized benefits
            Pollutant               reductions (tpy)         (3% Discount Rate)           (7% Discount Rate)
----------------------------------------------------------------------------------------------------------------
PM2.5...........................                   917  $210 to $510...............  $190 to $460.
----------------------------------------------------------------------------------------------------------------
                                           PM[bdi2].[bdi5] Precursors
----------------------------------------------------------------------------------------------------------------
SO2.............................                 6,262  $180 to $450...............  $170 to $410.
NOX.............................                 5,399  $26 to $64.................  $24 to $58.
                                 -------------------------------------------------------------------------------
    Total.......................  ....................  $420 to $1,000.............  $380 to $930.
----------------------------------------------------------------------------------------------------------------
\a\ All estimates are for the implementation year (2015) and are rounded to two significant figures so numbers
  may not sum across rows. All fine particles are assumed to have equivalent health effects but the benefit-per-
  ton estimates vary between precursors because each ton of precursor reduced has a different propensity to form
  PM2.5. Benefits from reducing HAP are not included.

    These benefits estimates represent the total monetized human health
benefits for populations exposed to less PM2.5 in 2015 from
controls installed to reduce air pollutants in order to meet these
standards. To estimate human health benefits of this rule, the EPA used
benefit-per-ton factors to quantify the changes in PM2.5-
related health impacts and monetized benefits based on changes in
SO2 and NOX emissions. These estimates are
calculated as the sum of the monetized value of avoided premature
mortality and morbidity associated with reducing a ton of
PM2.5 and PM2.5 precursor emissions. To estimate
human health benefits derived from reducing PM2.5 and
PM2.5 precursor emissions, we used the general approach and
methodology laid out in Fann, Fulcher, and Hubbell (2009).\13\
---------------------------------------------------------------------------

    \13\ Fann, N., C.M. Fulcher, B.J. Hubbell. 2009. ``The influence
of location, source, and emission type in estimates of the human
health benefits of reducing a ton of air pollution.'' Air Qual Atmos
Health (2009) 2:169-176.
---------------------------------------------------------------------------

    To generate the benefit-per-ton estimates, we used a model to
convert emissions of direct PM2.5 and PM2.5
precursors into changes in ambient PM2.5 levels and another
model to estimate the changes in human health associated with that
change in air quality. Finally, the monetized health benefits were
divided by the emission reductions to create the benefit-per-ton
estimates.
    These models assume that all fine particles, regardless of their
chemical composition, are equally potent in causing premature mortality
because the scientific evidence is not yet sufficient to support the
development of differential effects estimates by particle type.
Directly emitted PM2.5, SO2 and NOX
are the primary precursors affected by this rule. Even though we assume
that all fine particles have equivalent health effects, the benefit-
per-ton estimates vary between precursors depending on the location and
magnitude of their impact on PM2.5 levels, which drive
population exposure. For example, SO2 has a lower benefit-
per-ton estimate than direct PM2.5 because it does not form
as much PM2.5, thus, the exposure would be lower and the
monetized health benefits would be lower.
    It is important to note that the magnitude of the PM2.5
benefits is largely driven by the concentration response function for
premature mortality. Experts have advised the EPA

to consider a variety of assumptions, including estimates based on both
empirical (epidemiological) studies and judgments elicited from
scientific experts, to characterize the uncertainty in the relationship
between PM2.5 concentrations and premature mortality. For
this rule, we cite two key empirical studies, the American Cancer
Society cohort study \14\ and the extended Six Cities cohort study.\15\
In the RIA for this rule, which is available in the docket, we also
include benefits estimates derived from expert judgments and other
assumptions.
---------------------------------------------------------------------------

    \14\ Pope, et al., 2002. ``Lung Cancer, Cardiopulmonary
Mortality, and Long-term Exposure to Fine Particulate Air
Pollution.'' Journal of the American Medical Association 287:1132-
1141.
    \15\ Laden, et al., 2006. ``Reduction in Fine Particulate Air
Pollution and Mortality.'' American Journal of Respiratory and
Critical Care Medicine. 173: 667-672.
---------------------------------------------------------------------------

    The EPA strives to use the best available science to support our
benefits analyses. We recognize that interpretation of the science
regarding air pollution and health is dynamic and evolving. After
reviewing the scientific literature and recent scientific advice, we
have determined that the no-threshold model is the most appropriate
model for assessing the mortality benefits associated with reducing
PM2.5 exposure. Consistent with this recent advice, we are
replacing the previous threshold sensitivity analysis with a new LML
assessment. While a LML assessment provides some insight into the level
of uncertainty in the estimated PM mortality benefits, the EPA does not
view the LML as a threshold and continues to quantify PM-related
mortality impacts using a full range of modeled air quality
concentrations.
    Most of the estimated PM-related benefits in this rule would accrue
to populations exposed to higher levels of PM2.5. Using the
Pope, et al., (2002) study, 85 percent of the population is exposed at
or above the LML of 7.5 [micro]g/m\3\. Using the Laden, et al., (2006)
study, 40 percent of the population is exposed above the LML of 10
[micro]g/m\3\. It is important to emphasize that we have high
confidence in PM2.5-related effects down to the lowest LML
of the major cohort studies. This fact is important, because as we
estimate PM-related mortality among populations exposed to levels of
PM2.5 that are successively lower, our confidence in the
results diminishes. However, our analysis shows that the great majority
of the impacts occur at higher exposures.
    Every benefit analysis examining the potential effects of a change
in environmental protection requirements is limited, to some extent, by
data gaps, model capabilities (such as geographic coverage) and
uncertainties in the underlying scientific and economic studies used to
configure the benefit and cost models. Despite these uncertainties, we
believe the benefit analysis for this rule provides a reasonable
indication of the expected health benefits of the rulemaking under a
set of reasonable assumptions. This analysis does not include the type
of detailed uncertainty assessment found in the 2006 PM2.5
NAAQS RIA because we lack the necessary air quality input and
monitoring data to run the benefits model. In addition, we have not
conducted any air quality modeling for this rule. The 2006
PM2.5 NAAQS benefits analysis \16\ provides an indication of
the sensitivity of our results to various assumptions.
---------------------------------------------------------------------------

    \16\ U.S. Environmental Protection Agency, 2006. Final
Regulatory Impact Analysis: PM2.5 NAAQS. Prepared by
Office of Air and Radiation. October. Available on the Internet at
http://www.epa.gov/ttn/ecas/ria.html.
---------------------------------------------------------------------------

    It should be emphasized that the monetized benefits estimates
provided above do not include benefits from several important benefit
categories, including reducing other air pollutants, ecosystem effects
and visibility impairment. The benefits from reducing HAP have not been
monetized in this analysis, including reducing 20,000 tons of carbon
monoxide, 780 tons of HCl, 2.5 tons of lead, 1.8 tons of cadmium, 680
pounds of mercury, and 58 grams of total D/F each year. Although we do
not have sufficient information or modeling available to provide
monetized estimates for this rulemaking, we include a qualitative
assessment of the health effects of these air pollutants in the RIA for
this rule, which is available in the docket.
    For more information on the benefits analysis, please refer to the
RIA for this rulemaking, which is available in the docket.

III. NHSM Final Revisions

A. Statutory Authority

    The EPA is promulgating these regulations under the authority of
sections 2002(a)(1) and 1004(27) of the RCRA, as amended, 42 U.S.C.
6912(a)(1) and 6903(27). Section 129(a)(1)(D) of the CAA ((42 U.S.C.
7429) directs the EPA to establish standards for CISWIs, which burn
solid waste. Section 129(g)(6) of the CAA provides that the term
``solid waste'' is to be established by the EPA under RCRA. Section
2002(a)(1) of RCRA authorizes the agency to promulgate regulations as
are necessary to carry out its functions under the Act. The statutory
definition of ``solid waste'' is provided in RCRA section 1004(27).

B. NHSM Rule History

    The agency first solicited comments on how the RCRA definition of
solid waste should apply to NHSMs used as fuels or ingredients in
combustion units in an ANPRM, which was published in the Federal
Register on January 2, 2009 (74 FR 41). We then published a NHSM
proposed rule on June 4, 2010 (75 FR 31844), which the EPA issued in
final form on March 21, 2011 (76 FR 15456). The March 2011, NHSM final
rule codified the standards and procedures for identifying which non-
hazardous secondary materials are ``solid waste'' when used as fuels or
ingredients in combustion units.
    In October 2011, the agency announced it would be initiating new
rulemaking proceedings to revise certain aspects of the NHSM rule.\17\
On December 23, 2011, we then published a proposed rule, which
addressed specific targeted amendments and clarifications to the part
241 regulations (76 FR 80452). These proposed revisions and
clarifications were limited to certain issues on which the agency had
received new information, as well as targeted revisions that the agency
believed were appropriate in order to allow implementation of the rule
as the EPA originally intended.\18\ As stated throughout the preamble
to the proposed rule, the agency was not reopening the entire NHSM rule
for reconsideration and would not respond to comments directed toward
rule provisions that were not specifically identified in this
proposal.\19\ Therefore, any comments that were submitted outside the
scope of the proposal, or for which the EPA did not solicit comment,

are not addressed in this final rule, or in the Response to Comments
document that has been prepared for this final rule.
---------------------------------------------------------------------------

    \17\ See October 14, 2011, Letter from Administrator Lisa P.
Jackson to Senator Olympia Snowe. A copy of this letter has been
placed in the docket for today's rule (EPA-HQ-RCRA-2008-1873).
    \18\ For more information regarding the intent of the December
23, 2011, proposed rule, see 76 FR 80469. For more information
regarding the scope of the proposed rule, see 76 FR 80470-80474.
    \19\ For example, see 76 FR 80470: ``The EPA is soliciting
comment only on these targeted changes and is not reopening any
other issues in the final NHSM rule. Comments that go beyond the
scope of this narrow RCRA rulemaking will not be addressed by the
Agency when it finalizes today's proposed rule.'' See also 76 FR
80474 ``As noted above, the intent of this proposal is to identify
certain specific aspects of the rule which EPA is reconsidering and
on which it is soliciting public comment. The Agency is not
reopening the entire rule for reconsideration and will not respond
to comments directed toward rule provisions that are not
specifically identified in this proposal.'' and 76 FR 80482 ``The
Agency is not considering any change to the self-implementing,
mandatory nature of the Sec.  241.3 standards for individual
facilities and will not respond to any comments on this topic.''.
---------------------------------------------------------------------------

    The Agency also notes that even though the NHSM final rule will
become effective on April 8, 2013, existing facilities that currently
burn NHSMs will have a substantial amount of time before having to
comply with the CISWI standards, as the compliance date for existing
CISWI sources subject to CAA 129 standards is 5 years after the date of
publication of the CISWI final rule or 3 years after the state plan is
approved, whichever happens earlier. In addition, the Boiler MACT rule
provides until February 7, 2016, for existing sources to comply with
the standards. We recognize that new sources will have to comply with
these rules sooner than do existing sources. Thus, we believe that
there will be more than adequate time for persons to determine whether
or not a NHSM sent to a combustion unit is a solid waste.

C. Introduction--Summary of Regulations Being Finalized

    In today's rule, the EPA is finalizing certain amendments and
clarifications to the 40 CFR part 241 regulations on which we have
received new information, as well as specific targeted revisions that
are appropriate in order to allow implementation of the rule as the EPA
originally intended. The regulations being issued today are summarized
below. The intent of this summary is to give a brief overview of the
revised part 241 regulations. More detailed discussions, including the
agency's responses to comments received on the proposed rule and its
rationale for decisions being made in this final action, are included
in section III.D of this preamble. In addition, in an effort to aid the
regulated community, the EPA is including in the docket for today's
rule an informational redline/strikeout version that identifies the
specific changes to the regulatory text, as compared to the March 2011,
final rule.\20\
---------------------------------------------------------------------------

    \20\ This document has been titled, ``NHSM 2012 Final Rule
Regulation Changes'' and is placed in Docket No: EPA-HQ-RCRA-2008-
0329.
---------------------------------------------------------------------------

1. Revised Definitions
    In today's rule, the EPA is finalizing revisions to the three
definitions discussed in the proposed rule: (1) ``clean cellulosic
biomass,'' (2) ``contaminants,'' and (3) ``established tire collection
programs.'' In addition, based on comments received on the proposed
rule, the agency is also finalizing a revised definition of ``resinated
wood.'' These revised definitions will be codified in 40 CFR 241.2.
a. Clean Cellulosic Biomass
    In today's action, the EPA is issuing a revised definition of
``clean cellulosic biomass'' that: (1) Makes clear that the list of
biomass materials are examples within the definition and is not
intended to be an exhaustive list; and (2) provides a more
comprehensive list of clean cellulosic biomass to guide the regulated
community. These revisions do not change the agency's intent under the
March 2011 final rule, but identify additional materials that are
``clean cellulosic biomass,'' and, thus, are traditional fuels under
these regulations. A discussion of relevant comments regarding the
definition of clean cellulosic biomass, as well as our rationale for
making these determinations, can be found in section III.D.1.a of this
preamble.
b. Contaminants
    In today's action, the EPA is issuing a final definition of
``contaminants'' to clarify what constituents will be considered
contaminants for the purposes of the contaminant legitimacy criterion.
Revisions include: (1) The replacement of a reference to ``any
constituent that will result in emissions'' with a specific list of
constituents to be considered as contaminants based on their status as
a precursor to air emissions; (2) the removal from the definition of
specific CAA section 112(b) and 129(a)(4) pollutants that are not
expected to be found in any NHSM or are adequately covered elsewhere in
the definition; and (3) the removal of the phrase ``including those
constituents that could generate products of incomplete combustion''
from the definition. A discussion of relevant comments regarding the
contaminants definition, as well as our rationale for making these
determinations, can be found in section III.D.1.b of this preamble.
c. Established Tire Collection Programs
    In today's action, the EPA is finalizing a revised definition of
``established tire collection program'' in order to account for ``off-
specification'' (including factory scrap) tires that are contractually
arranged to be collected, managed and transported between a tire
manufacturer (including retailers or other parties involved in the
distribution and sale of new tires) and a combustor, which is analogous
to how scrap tires removed from vehicles are managed. The off-
specification tires are not removed from vehicles \21\ and are handled
under contractual arrangements which ensure they are not discarded. A
description of how the changes to the definition accommodate the
management of off-specification tires can be found in section III.D.1.c
of this preamble. In addition to the proposed changes, we are revising
the definition to specifically include tires that were not abandoned
and were received from the general public at tire collection program
events. A discussion of relevant comments regarding the definition, as
well as our rationale for making this determination, can be found in
section III.D.1.c of this preamble.
---------------------------------------------------------------------------

    \21\ ``Removal from vehicles'' had been a component of the
definition.
---------------------------------------------------------------------------

d. Resinated Wood
    In today's action, the EPA is issuing a revised definition of
``resinated wood'' that includes additional materials in order to be
more representative of the universe of resinated wood residuals that
are currently used as fuels throughout the wood product manufacturing
process. Revisions include: (1) Replacing the phrase ``containing resin
adhesives'' with the phrase, ``containing binders and adhesives,'' and
(2) specifically including ``off-specification resinated wood products
that do not meet a manufacturing quality or standard'' within this
definition. A discussion of relevant comments regarding the resinated
wood definition, as well as our rationale for making this
determination, can be found in section III.D.3.b of this preamble.
2. Contaminant Legitimacy Criterion for NHSM Used as Fuels
    In today's action, the EPA is issuing in final form a revised
contaminant legitimacy criterion for NHSMs used as fuels to provide
additional details on how contaminant comparisons between NHSMs and
traditional fuels may be made. Revisions include: (1) The ability to
compare groups of contaminants where technically reasonable; (2) the
clarification that ``designed to burn'' means can burn or does burn,
and not necessarily permitted to burn; (3) the ability to use
traditional fuel data from national surveys and other sources beyond a
facility's current fuel supplier; and (4) the ability to use ranges of
traditional fuel contaminant levels when making contaminant
comparisons, provided the variability of NHSM contaminant levels is
also considered. A discussion of relevant comments regarding the
contaminant legitimacy criterion for NHSMs used as fuels, as

well as our rationale for making these determinations, can be found in
section III.D.2 of this preamble.
3. Categorical Non-Waste Determinations for Specific NHSM Used as Fuels
    In today's final rule, the agency is codifying determinations that
certain NHSMs are non-wastes when used as fuels. Based on all available
information, the EPA has determined that the following NHSMs are
categorically not a solid waste when burned as a fuel in combustion
units: (1) Scrap tires that are not discarded and are managed under the
oversight of established tire collection programs, including tires
removed from vehicles and off-specification tires; (2) resinated wood;
(3) coal refuse that has been recovered from legacy piles and processed
in the same manner as currently-generated coal refuse; and (4)
dewatered pulp and paper sludges that are not discarded and are
generated and burned on-site by pulp and paper mills that burn a
significant portion of such materials where such dewatered residuals
are managed in a manner that preserves the meaningful heating value of
the materials.
a. Scrap Tires
    In today's action, the agency is adding scrap tires that are not
discarded and are managed under the oversight of established tire
collection programs, including tires removed from vehicles and off-
specification tires (including factory scraps), to the categorical list
of non-waste fuels (see 40 CFR 241.4(a)(1)) as proposed. Based on this
categorical non-waste determination, facilities burning the scrap tires
that qualify for the provision will not need to demonstrate that this
NHSM meets the legitimacy criteria on a site-by-site basis. Further,
the addition to the new categorical non-waste provision at 40 CFR
241.4(a)(1) eliminated the need for the previous scrap tire provision
at 40 CFR 241.3(b)(2)(i),\22\ which has been removed and reserved in
today's final rule. A discussion of relevant comments regarding the
scrap tire provision, as well as our rationale for making this
determination, can be found in section III.D.3.a of this preamble.
---------------------------------------------------------------------------

    \22\ The scrap tire provision in the 2011 NHSM final rule is now
removed and the section reserved in today's final rule: ``(b) The
following non-hazardous secondary materials are not solid wastes
when combusted:
     (2) The following non-hazardous secondary materials that have
not been discarded and meet the legitimacy criteria specified in
paragraph (d)(1) of this section when used in a combustion unit (by
the generator or outside the control of the generator):
    (i) Scrap tires used in a combustion unit that are removed from
vehicles and managed under the oversight of established tire
collection programs.''
---------------------------------------------------------------------------

b. Resinated Wood
    In today's action, the agency is listing resinated wood as a non-
waste fuel in 40 CFR 241.4(a)(2), as proposed. The EPA has evaluated
resinated wood and, based on all available information, including
consideration of the legitimacy criteria, as well as other relevant
factors, has determined that resinated wood is not a solid waste when
used as a fuel. Based on this categorical non-waste determination,
facilities burning resinated wood residuals as a fuel will not need to
demonstrate that this NHSM meets the legitimacy criteria on a site-by-
site basis.
    Further, the addition of this categorical non-waste determination
(40 CFR 241.4(a)(2)) eliminated the need for the previous resinated
wood provision at 40 CFR 241.3(b)(2)(ii),\23\ which has been removed
and reserved in today's final rule. A discussion of relevant comments
regarding the categorical non-waste determination for resinated wood,
as well as our rationale for making this determination, can be found in
section III.D.3.b of this preamble.
---------------------------------------------------------------------------

    \23\ The resinated wood provision in the 2011 NHSM final rule is
now removed and the section reserved in today's final rule: ``(b)
The following non-hazardous secondary materials are not solid wastes
when combusted:
     (2) The following non-hazardous secondary materials that have
not been discarded and meet the legitimacy criteria specified in
paragraph (d)(1) of this section when used in a combustion unit (by
the generator or outside the control of the generator):
    (ii) Resinated wood used in a combustion unit.''
---------------------------------------------------------------------------

c. Coal Refuse
    In today's action, the agency has determined that coal refuse that
has been recovered from legacy piles and processed in the same manner
as currently-generated coal refuse, is a non-waste fuel in 40 CFR
241.4(a)(3). This determination is based on the fact that: (1)Legacy
coal refuse processed in the same manner as currently-generated coal
refuse meets the definition of processing (as codified in 40 CFR
241.2); and (2)the EPA's assessment that such materials meet the
legitimacy criteria for fuels (as codified in 40 CFR 241.3(d)(1)) when
compared to currently-generated coal refuse, which the agency considers
to be within the definition of a traditional fuel (as codified in 40
CFR 241.2). Based on this categorical non-waste determination,
facilities burning these materials as a fuel will not need to
demonstrate that this NHSM meets the legitimacy criteria on a site-by-
site basis. A discussion of relevant comments regarding the categorical
non-waste determination for coal refuse that is recovered from legacy
piles and processed, as well as our rationale for making this
determination, can be found in section III.D.5.b of this preamble.
d. Pulp and Paper Sludge
    In today's action, the EPA has determined that dewatered pulp and
paper sludges that are not discarded and are generated and burned on-
site by pulp and paper mills that burn a significant portion of such
materials where such dewatered residuals are managed in a manner that
preserves the meaningful heating value of the materials are non-waste
fuels in 40 CFR 241.4(a)(4). This determination for pulp and paper
sludge as a categorical non-waste represents the agency's finding,
after balancing the regulatory legitimacy criteria with other relevant
factors, that the burning of this material is an integral part of
facility operations, and as described in the categorical listing is for
energy recovery and not discard. Based on this categorical non-waste
determination, facilities meeting the description of this determination
and burning these materials as a fuel will not need to demonstrate that
this NHSM meets the legitimacy criteria on a site-by-site basis. A
discussion of relevant comments regarding the categorical non-waste
determination for pulp and paper sludges, as well as our rationale for
making this determination, can be found in section III.D.5.a of this
preamble.
4. Rulemaking Petition Process for Other Categorical Non-Waste
Determinations (40 CFR 241.4(b))
    In today's final rule, the agency is finalizing a rulemaking
petition process that provides persons with an opportunity to submit a
rulemaking petition to the Administrator, seeking a categorical
determination for additional NHSMs to be listed in 40 CFR 241.4(a) as
non-waste fuels. The process for submitting a rulemaking petition to
the agency, as well as the factors a successful application must
include, is listed in 40 CFR 241.4(b). A discussion of relevant
comments regarding the petition process for the categorical listings,
as well as our rationale for the categorical rulemaking petition
process, can be found in section III.D.4 of this preamble.
5. Streamlining of the 40 CFR 241.3(c) Non-Waste Determination Petition
Process
    In today's final rule, the agency is streamlining the non-waste
determination provisions under 40 CFR 241.3(c). The public
participation process was streamlined to

accommodate petitions that apply to multiple combustors. In particular,
the regulations were adjusted to indicate that the appropriate office
in the EPA headquarters may handle petitions that cross multiple
regions. Furthermore, if a determination is made that the NHSM is a
non-waste, the decision will be retroactive and apply on the date the
petition was submitted. A discussion of relevant comments regarding the
streamlining of the 40 CFR 241.3(c) non-waste determination petition
process, as well as our rationale for the streamlining changes made to
the non-waste determination process, can be found in section III.D.6 of
this preamble.
6. Revised Introductory Text for 40 CFR 241.3(a)
    In today's final rule, the agency has decided not to revise the
introductory text of 40 CFR 241.3(a). In its December 2011 proposed
rule, the EPA considered revising this introductory text to state that
NHSMs are ``presumed to be'' solid wastes, rather than ``are'' solid
wastes. While the proposed change was not expected to be a substantive
change to the rule, but merely a reflection of the record at the time,
it did engender some confusion among commenters. Based on the comments
received, we have decided not to issue revised introductory text 40 CFR
241.3(a) and, thus, this section will continue to read as codified in
the March 2011 NHSM final rule. A discussion of relevant comments
regarding the introductory text of 40 CFR 241.3(a), as well as our
rationale for this decision, can be found in section III.D.7 of this
preamble.

D. Comments on the Proposed Rule and Rationale for Final Decisions

    In this section, the EPA addresses major comments the agency
received regarding the targeted revisions that were proposed to certain
part 241 provisions in the December 23, 2011, proposal. In discussing
the comments received on the proposal, we also provide the rationale
for making the revisions that are finalized in today's action. As
previously discussed, the agency specifically stated that it would not
address comments that go beyond the scope of this narrow RCRA
rulemaking.
1. Revised Definitions
a. Clean Cellulosic Biomass
    The proposed rule suggested revising the March 2011 definition of
``clean cellulosic biomass'' to list additional examples of biomass
materials that are appropriately included within this definition. These
fuels are not secondary materials or solid wastes unless discarded.
Clean biomass is ``biomass that does not contain contaminants at
concentrations not normally associated with virgin biomass materials''
(codified in 40 CFR 241.2).
    This regulatory revision would not change the agency's intent under
the March 2011 final rule, but would identify additional materials that
are ``clean cellulosic biomass,'' and, thus, would be a traditional
fuel under these regulations. While the list of clean biomass materials
is only illustrative and not exhaustive, it is now more comprehensive
than the list that appeared in the definition included in the 2011 NHSM
final rule.
    One of the materials within the definition is clean C&D wood. In
light of some confusion in comments regarding C&D wood, the EPA is
clarifying the meaning of the term in the definition of ``clean
cellulosic biomass.'' Construction & demolition wood actually may be
placed into different categories, depending upon its origin. In
accordance with the traditional fuels definition in section 241.2,
clean C&D wood could be combusted as a traditional fuel if it does not
contain contaminants at concentrations not normally associated with
virgin wood.
    However, the final NHSM rule also addressed C&D wood that may
contain contaminated material.\24\ There is no need to repeat these
discussions here, except to clarify what the final rule means. In
general, contaminated C&D wood that has been processed to remove
contaminants, such as lead-painted wood, treated wood containing
contaminants, such as arsenic and chromium, metals and other non-wood
materials, prior to burning, likely meets the processing and legitimacy
criteria for contaminants, and thus can be combusted as a non-waste
fuel (see further discussion in response to comments below).
---------------------------------------------------------------------------

    \24\ See 76 FR 15485.
---------------------------------------------------------------------------

    Comment: One commenter noted that the EPA's specific inclusion of
``untreated wood pallets'' implicitly accepts that small amounts of
non-wood material inherent to the pallets, such as screws or plastic
fasteners, do not render those materials solid waste under the rule,
and de minimis amounts of non-biomass material would not require these
types of materials to be burned in incinerators under the CISWI rule.
    Another commenter requested that the EPA reconsider use of the word
``untreated'' when referring to wood pallets. The commenter argues that
the EPA does not define the word ``untreated'' and its use could create
confusion. Rather, the commenter recommends that ``untreated'' be
replaced with the word ``clean,'' which is an adjective used in the
definition to distinguish other materials (e.g., ``clean construction
and demolition wood'').
    Response: Wood pallets are refurbished or recycled for other uses
by pallet recyclers. When the useful life of the pallet is finished,
the recyclers typically remove the small amount of non-wood material
inherent to pallets that would inhibit combustion, such as screws or
plastic fasteners. The pallets are then ready for use as fuel, and the
non-wood material would not impact whether the material can be burned
in combustion units that meet the CAA section 112 emission standards.
The agency is not aware of instances where the pallets are used as fuel
directly by the original users and non-wood material is left remaining
in the pallet. Such pallets would not be considered clean cellulosic
biomass under the rule.
    With respect to the other comment, the EPA does not agree, that the
term ``untreated'' wood pallet be replaced with the term ``clean'' wood
pallet. The term ``clean'' is defined in the traditional fuels
definition as described above, and applies to all the materials listed
in the definition of clean cellulosic biomass, which includes untreated
wood pallets. It would be redundant to define ``clean'' biomass as
including ``clean'' wood pallets. The point is that some wood pallets
may contain treated wood, such as CCA treated wood, and inclusion of
the term ``untreated'' with wood pallet would help emphasize that such
treated wood would not be considered ``clean'' under the definition of
clean cellulosic biomass.
    Comment: Several commenters indicated that the definition of clean
cellulosic biomass remains ambiguous because it continues to include
the caveat that: ``Clean biomass is biomass that does not contain
contaminants at concentrations not normally associated with virgin
biomass materials.'' Thus, notwithstanding the EPA's attempt at
expanding the definition of clean cellulosic biomass, the commenters
believed that this sentence should be removed because it perpetuates
uncertainty. It is not clear what comparisons are permissible and what
concentration levels are appropriate.
    The commenters also indicated that this sentence perpetuates the
EPA's erroneous interpretation of its authority under RCRA. A material
does not become a waste when burned for energy recovery just because it
may contain contaminants--prior to combustion--not normally associated
with virgin biomass. It becomes a waste only if it is

combusted for the purpose of disposal, rather than for energy recovery.
    Response: The agency disagrees with the commenter that defining the
term ``clean'' leads to ambiguity in identifying which materials are
clean cellulosic biomass. On the contrary, defining the term ``clean''
is meant to ensure that contaminated cellulosic material being burned,
such as lead-painted wood or arsenic treated wood, does not introduce
contaminants (as defined in 40 CFR 241.2) not normally associated with
virgin biomass materials.
    The agency wishes to emphasize, however, that determinations that
the cellulosic biomass used as a fuel or ingredient is clean, do not
presuppose any testing of contaminant levels. Persons can use expert or
process knowledge of the material to justify decisions regarding
presence of contaminants.
    With respect to the comment that burning of contaminated material
does not make it a waste, the agency has not reopened this issue for
this rule and stands by its responses in the rulemaking record for the
March 2011 final rule.\25\
---------------------------------------------------------------------------

    \25\ See, for example, 76 FR 15523-4: ``If a non-hazardous
secondary material contains contaminants that are not comparable to
those found in traditional fuels, and those contaminants are related
to pollutants that are of concern at solid waste combustion units,
then it follows that discard is occurring. The contaminants in these
cases could not be considered a normal part of a legitimate fuel and
are being discarded, either through destruction in the combustion
unit or through releases into the air. Units that burn such
materials are therefore most appropriately regulated under the CAA
section 129 standards for solid waste incinerators.'' See also 76 FR
15485, which states: ``[A]s we have noted previously, the criterion
or test for determining whether a material is burned as a waste or a
commodity fuel is the level of the contaminant in the secondary
material itself--that is destruction of contaminants indicates a
waste treatment activity rather than a commodity fuel.''
---------------------------------------------------------------------------

    Comment: One commenter provided the example of whether treated
seeds that contain additives are considered contaminants in virgin
biomass. These additives may not be found in virgin seeds but are not
harmful at the concentrations found in the seeds. The commenter
questioned whether any concentration above ``natural'' (concentration
levels found in virgin material), especially when combusted as fuel,
would be prohibited and require additional waste regulation.
    Response: Seeds may be treated with pesticides and hormones to aid
in germination. Such chemicals do not generally include contaminants as
defined in section 241.2; therefore, such treated seeds would be
considered clean cellulosic biomass.
    Comment: Several commenters indicated that, as part of the EPA's
changes in the definition of clean cellulosic biomass, it is proposing
to consider treated or painted wood the same as ``virgin'' wood if it
has lower than de minimis levels of contamination. While adoption of
numerical values in the rule would require additional provisions for
measurements and would require additional notice, the commenter
believes that such clarity is important for successful implementation
of the rule. Such limits would be applied to ``clean'' C&D material,
for instance, among other potential fuel types. The term de minimis is
not defined numerically in the proposed rule and the commenters argue
that without a specific numerical de minimis limit, sources would not
have a clear understanding of whether they fall under the CISWI or
hazardous waste incinerator rules. The commenter recommended that the
EPA define and allow for public comment on the levels associated with
the term de minimis and base the de minimis levels on contaminant
levels found in typical ``virgin'' wood.
    Response: Regarding the addition of a definition for de minimis
amounts of contaminants remaining in processed wood, the agency does
not believe it appropriate to identify specific concentration levels.
Rather, the agency interprets de minimis as that term is commonly
understood; i.e., insignificant or negligible amounts of contamination
such as small wood sliver containing lead paint).
    As indicated above, there also appears to be confusion among
commenters regarding two different categories of C&D wood--``clean C&D
wood'' that is a traditional fuel, and C&D wood that has been processed
to remove contaminants. Under the 2011 NHSM final rule, C&D wood that
has been processed to remove contaminants, such as lead-painted wood,
treated wood containing contaminants, such as arsenic and chromium,
metals and other non-wood materials, prior to burning, likely meets the
processing and legitimacy criteria for contaminants, and thus can be
combusted as a non-waste fuel but would not be considered ``clean C&D
wood.'' Such C&D wood may contain de minimis amounts of contaminants
and other materials provided it meets the legitimacy criteria for
contaminant levels. To meet the contaminant legitimacy criterion,
concentration levels of contaminants in the processed C&D wood must be
comparable to or less than the levels in the traditional fuel the unit
was designed to burn, whether wood or another traditional fuel (see
section III.D.2 for a discussion on contaminant comparisons). In
contrast, ``clean C&D wood'' is a traditional fuel that does not
require processing and meets the definition of ``clean'' (i.e., C&D
wood that does not contain contaminants at concentrations not normally
associated with virgin biomass (wood)). Thus, de minimis amounts of
contaminants and other material appropriate for processed C&D wood
would not be appropriate for clean wood that is a traditional fuel.
    Comment: One commenter argued that states should have discretion
about how to determine appropriate fuel quality but it should be no
less stringent than limits set by the EPA. There should be a
distinction between de minimis levels of contamination in C&D wood and
a fuel quality standard.
    Response: We do not necessarily disagree with the commenter. That
is, as discussed in the final rule, part 241 does not preempt a state's
statutory or regulatory standards and states are free to establish fuel
quality standards for C&D wood. However, we would also note that as
solid waste is defined by the EPA under RCRA, such state standards
would not necessarily impact the status of the material as it relates
to which combustion units are subject to CAA section 129 (56 FR 15546).
b. Contaminants
    The December 2011 rule proposed to clarify what constituents will
be considered contaminants by making the definition of ``contaminants''
more specific. However, the proposal maintained the fundamental
approach--and was intended to cover the same constituents--as the March
2011 final rule.
    The March 2011 final rule and the December 2011 proposed rule
identified the same three ways a chemical can be labeled a contaminant.
First, it may be one of the 187 HAP currently listed in CAA section
112(b); second, it may be one of the nine pollutants listed under CAA
section 129(a)(4); and third, it may be one of a handful of chemicals
whose combustion will result in the formation of listed CAA section
112(b) and section 129(a)(4) pollutants (e.g., sulfur that will result
in SO2).
    The definition proposed in December provided clarification by
listing the constituents that belong to the third group.\26\
Specifically, the proposed

revision replaced a potentially ambiguous reference to ``any
constituent that will result in emissions'' with the four specific
elements the agency intended to be considered as contaminants
(chlorine, fluorine, nitrogen, and sulfur) based on their status as a
precursor to air emissions. In all four cases, the CAA pollutant itself
(e.g., SO2) is not likely to be present in the NHSM prior to
combustion, and the only way to measure constituents prior to
combustion ``that will result in emissions'' of that pollutant is to
measure a known precursor (e.g., sulfur) instead. For each of the four
precursor elements listed as contaminants in the proposal, the expected
fate for the precursor during combustion is formation of the
aforementioned pollutant and the precursor makes no substantive
contribution to the material's value as a fuel. For these reasons, the
agency proposed to specifically identify chlorine, fluorine, nitrogen,
and sulfur as contaminants in place of HCl, HF, NOX and
SO2. By limiting the list of precursors considered
contaminants to these four elements, the revised definition also made
clear that the agency did not intend to include other elements present
in contaminants (such as hydrogen and carbon) as contaminants
themselves.
---------------------------------------------------------------------------

    \26\ Eleven metal elements directly identified in CAA section
112(b) were also listed in the proposed definition to provide the
regulated community with a complete list of elements that are
considered ``contaminants'' under the rule.
---------------------------------------------------------------------------

    The December 2011 proposed rule also removed from the definition of
contaminants those pollutants in CAA sections 112(b) and 129(a)(4) that
we do not expect to find in any NHSM. Specifically:
     Chlorine gas, HCl, HF, NOX, and SO2
were removed from the definition because they are unlikely to be found
in NHSMs prior to combustion and had been replaced by the elements
chlorine, fluorine, nitrogen and sulfur as discussed above;
     Fine mineral fibers were removed because they are releases
from the manufacturing and processing (not combustion) of non-
combustible rock, glass or slag into mineral fibers;
     Particulate matter and coke oven emissions were removed
because they are products of combustion unlikely to exist in NHSMs
prior to combustion;
     Cresol isomers m-cresol, o-cresol, and p-cresol were
removed because the listed pollutant cresols/cresylic acid includes
these three isomers;
     Xylene isomers m-xylene, o-xylene, and p-xylene were
removed because the listed pollutant xylenes includes these three
isomers; and
     Diazomethane, white phosphorus, and titanium tetrachloride
were removed because their high reactivity makes their presence in
NHSMs very unlikely.
    In addition, two phrases present in the March 2011 final rule
``contaminants'' definition were not included in the December 2011
proposed rule definition. First, the phrase concerning constituents
``that will result in emissions of the air pollutants'' was removed
since the regulated community had expressed confusion that in
determining whether or not a NHSM meets the contaminant legitimacy
criterion, emissions from the combustion unit were to be evaluated. The
EPA disagreed and directed readers to the language in sections
241.3(d)(1)(iii) and 241.3(d)(2)(iv). These sections state that
contaminant comparisons are based on the presence of contaminants in
the NHSM (or products made from NHSMs in the case of ingredients), not
the resulting emissions. The proposed revision also inserted the phrase
``prior to combustion'' into the contaminants definition to further
emphasize that the NHSMs, not the emissions that result from NHSMs, are
to be evaluated when conducting contaminant comparisons. The rationale
for evaluating the NHSM, and not emissions, can be found in the record
for the March 2011 final rule.\27\ The proposal merely added language
to ensure the rule is consistent with the agency's intent.
---------------------------------------------------------------------------

    \27\ For example, see 76 FR 15524-15525.
---------------------------------------------------------------------------

    The second phrase proposed to be removed from the March 2011 final
rule definition was a reference to ``those constituents that could
generate products of incomplete combustion,'' also referred to as PICs.
This reference was removed from the definition because it was
duplicative and potentially misleading. Specifically, this phrase was
not necessary because all PICs that the agency considers air
pollutants--including dioxins, dibenzofurans, PCBs and PAHs--are listed
in CAA sections 112(b) or 129(a)(4) and are thus already included in
the ``contaminants'' definition. More importantly, the phrase was
potentially misleading because PIC formation depends heavily on
combustion conditions, such as air/fuel ratio and mixing. These
conditions are controlled to limit emissions and neither these
conditions nor emissions are the subject of this rule. The NSHM itself
is the subject of this rule. Thus, the removal of both phrases
clarified, but did not alter, the constituents subject to the
contaminant legitimacy criterion.
    The EPA believes that comments have not changed the basis for
listing specific precursors to air emissions as contaminants, nor have
they changed the basis for either excluding specific constituents from
the definition or removing the references to ``that will result in
emissions of the air pollutants'' and ``constituents that could
generate products of incomplete combustion'' from the definition. Thus,
the EPA is adopting the reasoning from the proposal and revising the
definition of contaminants to incorporate these concepts.
    The EPA has decided, however, to make several modifications to the
regulatory language of the December 2011 proposed rule based on
comments received and information in the rulemaking record. First, in
the final definition issued today, precursors will only be considered
contaminants for NHSMs used as fuels; precursors will not be considered
contaminants for NHSMs used as ingredients. Furthermore, precursors
will not be considered contaminants if they do not form their
corresponding pollutants. Also, opacity has been removed from the
contaminants definition. Finally, the phrase ``prior to combustion''
has not been inserted into the contaminants definition, as had been
proposed. Contaminants in NHSMs used as fuel in combustion units must
still be evaluated prior to combustion, and persons must still evaluate
the NHSM itself (not emissions), but the agency has determined that the
topic of when to evaluate contaminants is more appropriate to address
in the legitimacy criteria than in the contaminants definition.
    Additional reasoning for keeping the rule provisions as proposed,
and for any modifications to the proposed language, are described in
the following responses to comments.
    Comment: Several commenters stated that the definition of
contaminants should focus on contaminants released as combusted
emissions. One commenter argued that contaminants should be compared
between emitted contaminants and emission standards. A second commenter
reiterated previous comments that contaminant levels should be related
to the air emissions and not the content of the material. For support,
commenters cited that the EPA reversed its position in the proposal by
using possible air emissions as the basis for establishing what
contaminants need to be compared.
    Response: The EPA has previously stated that contaminant levels
before and after combustion can be important indicators of legitimacy
and it maintains the position from the March 2011 final rule that non-
waste fuels must be similar in composition to traditional

fuels prior to combustion.\28\ Because combustion and emission control
processes can destroy or remove contaminants, a comparison of emissions
profiles alone only tells one how well the combustion unit is
operating, not whether the NHSM is being used as a legitimate non-waste
commodity fuel.\29\
---------------------------------------------------------------------------

    \28\ See 76 FR 15525.
    \29\ Id.
---------------------------------------------------------------------------

    The EPA disagrees with the comment that the agency reversed its
position on the consideration of emissions in the proposal by including
precursors to air emissions as contaminants. The agency notes that a
difference exists between comparing ``emissions'' and comparing
``contaminants that will result in emissions,'' the exact language used
in the March 2011 final rule. The EPA has clarified what it intended by
``contaminants that will result in emissions'' in today's final action.
This clarification involves the listing of specific precursors known to
result in emissions of air pollutants when combusted; it also involves
the removal of specific pollutants known not to be present in NHSMs.
    Comment: Two commenters expressed concern that the proposed
definition of contaminants conflicted with the contaminant legitimacy
criterion for NHSMs used as ingredients in combustion units. Commenters
stated that both the definition of contaminants, as proposed, and the
existing contaminant legitimacy criterion for ingredients were clear
when read separately but were contradictory when taken together. The
commenters encouraged the EPA to clarify the regulatory text.
Specifically, the commenters noted that for ingredients, contaminants
could not be evaluated prior to combustion and then used to compare
products produced using NHSMs to products produced using traditional
materials.
    Response: The EPA has decided not to include language from the
December 2011 proposed rule in the definition of contaminants that
emphasized when NHSM contaminant levels are to be evaluated (i.e.,
before or after combustion). While the proposed additional language
made clear that NHSMs used as a fuel were to be evaluated for
contaminants ``prior to combustion,'' the agency agrees with the two
commenters who argued that the proposed language conflicts with the
contaminant legitimacy criterion for ingredients. The contaminant
criterion for ingredients requires comparisons to be made between
products produced with and without NHSMs, but until the products exist,
they cannot be compared.
    As such, the agency has decided not to adopt the proposed
additional language addressing when contaminants are to be evaluated in
the definition of contaminants. The agency proposed similar language in
the December 2011 rule addressing this topic in the contaminant
legitimacy criterion and the agency is adopting that language in
today's final rule. The agency has determined that the legitimacy
criteria themselves (40 CFR 241.3(d)(1)(iii) for fuels and 40 CFR
241.3(d)(2)(iv) for ingredients) are more appropriate places to address
this topic.
    The EPA has also decided to add language to the definition of
contaminants clarifying that the specification of particular precursors
to air emissions (i.e., chlorine, fluorine, nitrogen and sulfur) as
contaminants does not apply to the contaminant legitimacy criterion for
ingredients. As identified by the commenters, the contaminant criterion
for ingredients requires comparisons to be made between products
produced with and without NHSMs. Products can only be compared after
combustion has occurred, at which point there will be no benefit to
measuring levels of precursors.
    The agency also notes that it does not envision a situation where
NHSMs containing chlorine, fluorine, nitrogen or sulfur would be used
as ingredients in such a way that would emit higher levels of HCl, HF,
NOX or SO2 than would be emitted using
traditional ingredients without the material being considered a solid
waste. In all cases, ingredients must provide a valuable contribution
to the product being produced, and that product must itself be
valuable, in order to not be considered a solid waste. For an
ingredient to provide value, the agency expects the ingredient to
remain in a product rather than be destroyed or released via emissions.
This is a key reason why the contaminant legitimacy criterion for
ingredients focuses on products (i.e., toxics along for the ride)
rather than emissions. Furthermore, the legitimacy criteria for
ingredients cannot be used to avoid the legitimacy criteria for fuels
if the material is being used for both purposes.
    Comment: Several commenters questioned the rationale for including
precursors to air emissions as ``contaminants'' under the proposed
revised definition. Some indicated that the concept is far removed from
the true meaning of ``discard,'' with one comment stating that the EPA
has no legal, rational or scientific basis for considering the presence
of sulfur or nitrogen in NHSMs as evidence of intent to discard
SO2 or NOX during combustion. To support this
argument, the commenter first noted that the EPA has no record basis
for assuming that the intent of the combustor is to discard the
constituent, rather than to generate energy. Second, the commenter
noted that whether or not a boiler has emissions of regulated air
pollutants, such as SO2 or NOX when it combusts a
precursor will depend, not on an intent to discard these pollutants,
but on boiler operation and design.
    Two commenters also stated that the preamble discussion on
precursors demonstrates how far removed the EPA's rationale for this
rulemaking is from the concept of discard. They noted that the EPA is
requiring combustors to document and keep records regarding the fact
that CO is not present in NHSMs, and, under CISWI, would identify the
NHSM as waste if this documentation is not maintained. The commenters
failed to see how this has anything to do with a determination that a
material is a waste under RCRA.
    Response: The EPA disagrees with these comments. Precursors to
emissions of identified air pollutants are important and appropriate to
address as contaminants in NHSMs prior to combustion. It is also
necessary to tailor the definition of contaminants to the realities of
the combustion process, during which precursors present in NHSMs used a
fuel--many of which are solid or liquid--are transformed into air
pollutants.
    However, the agency agrees with those commenters who argued that
the revised definition, as proposed, may be too broad with regard to
precursors that may not form air pollutants in all cases. For example,
if the combustion of nitrogen does not form NOX in a
particular situation, the agency did not intend in its December 2011
proposed rule to consider nitrogen as a contaminant in that particular
situation.\30\ The EPA noted in the proposed rule that chlorine,
fluorine, nitrogen and sulfur will form pollutants of concern in most
circumstances, but the agency does acknowledge that specific
technologies and practices may prevent these transformations from
happening in the first instance, particularly with regard to nitrogen
(one

example being the use of Low NOX burners with Over-Fire
Air). Thus, the contaminants definition issued in today's final rule
does not consider constituents that are normally precursors to CAA
section 112(b) or 129(a)(4) pollutants to be contaminants if a specific
technology or practice prevents them from forming their corresponding
pollutants.
---------------------------------------------------------------------------

    \30\ See March 16, 2012 Response from James R. Berlow, Director,
Program Implementation and Information Division, EPA's Office of
Resource Conservation and Recovery to Fadi K. Mourad, DTE Energy
Services, Inc. A copy of this response letter has been placed in the
docket for today's rulemaking and is also available at http://www.epa.gov/epawaste/nonhaz/define/index.htm.
---------------------------------------------------------------------------

    The definition codified in 40 CFR 241.2 only includes chlorine,
fluorine, nitrogen and sulfur as contaminants in cases where
``combustion will result in the formation of hydrogen chloride (HCl),
hydrogen fluoride (HF), nitrogen oxides (NOX), or sulfur
dioxide (SO2).'' When compared to the December 2011 proposed
rule, the only constituents no longer considered contaminants due to
this modification are chlorine that will not form HCl during
combustion, fluorine that will not form HF during combustion, nitrogen
that will not form NOX during combustion and sulfur that
will not form SO2 during combustion. This is consistent with
the March 2011 NHSM final rule, under which these constituents would
not be contaminants when they would not ``result in emissions'' of CAA
section 112(b) or section 129(a)(4) pollutants.
    Although the EPA is not currently aware of any technologies or
practices that prevent chlorine, fluorine or sulfur in NHSMs from
forming their associated pollutants during combustion (the EPA is aware
of such examples with nitrogen), the agency considers it reasonable and
appropriate to adopt the same language for all four precursors to allow
for future technological advances preventing the transformation of
these elements into pollutants during combustion.
    Comment: One commenter stated that the consideration of precursors
to air emissions as contaminants could be used to make the most
fundamental of all elements, hydrogen, a contaminant because it is
present in nearly all regulated pollutants. The presence of hydrogen in
a NHSM could then be considered evidence of intent to discard
pollutants that contained hydrogen.
    Response: Under the proposed contaminants definition, only the
specific precursor elements listed (chlorine, fluorine, nitrogen and
sulfur) are considered contaminants. The EPA determined in the
proposal, and adopts as its final decision today, that these are the
only four precursors necessary to evaluate when comparing contaminants
between NHSMs and traditional fuels. The agency specifically decided
not to include hydrogen on this list. Whereas combustion of chlorine,
fluorine, nitrogen and sulfur typically leads to the formation of CAA
section 112(b) or 129(a)(4) air pollutants, combustion of hydrogen
typically leads to the formation of water vapor.
    Comment: Several commenters opposed the inclusion of precursors as
contaminants on the ground that the formation of related pollutants
depends more on boiler operation and design, process chemistry and
feedstock characteristics than on the levels of precursors present in
the NHSMs.
    Response: The EPA recognizes that unit design and operating
conditions can impact the transformation of chlorine, fluorine,
nitrogen and sulfur into air pollutants. Rather than viewing this as a
reason to ignore the pollutants these elements commonly form, the
agency views this as further evidence why precursor levels must be
considered when determining which set of CAA standards--which in turn
regulate unit operating conditions--should apply.
    Comment: Two commenters suggested that the EPA follow a different
approach for defining contaminants and use a method similar to what the
agency used for the used oil specification in 40 CFR 279.11. In each
case, the commenter suggested that for NHSMs, the definition of
contaminants should be limited to sulfur, nitrogen, chlorine, Cd, Hg
and lead because those are the elements Congress addressed in CAA
section 129. This approach, they argued, would be similar to what the
EPA did when developing the used oil specifications. The point the
commenters wished the agency to draw from the used oil specification
approach is that it addressed elemental species, as opposed to
individual compounds. Using sulfur as an example, the commenters
reasoned that it is the underlying presence of sulfur-bearing materials
in the NHSMs, as opposed to individual sulfur-containing compounds on
the section 112(b) list, which effects emissions of SO2.
    Response: The EPA disagrees with the approach outlined by the
commenters and has issued a final definition of contaminants based on
both the CAA section 112(b) and the CAA section 129(a)(4) lists, as was
proposed. We do agree with the commenters, however, that identifying
precursors that will form certain CAA pollutants in the definition of
contaminants is appropriate. The approach outlined by the commenters
appears to be based on two premises that the EPA has previously
considered and decided not to adopt.
    First, the commenters do not think the definition of contaminants
should reference both the CAA section 112(b) and CAA section 129(a)(4)
lists. The agency previously explained its decision to use both lists
in the March 2011 final rule and does not believe comments have offered
any new information that would change the basis for this decision. The
EPA previously discussed that both lists of constituents are
appropriate because both lists are to be considered by the EPA when
developing emission standards.\31\ Furthermore, the agency has
previously explained that CAA section 129 provides that the term
``solid waste'' shall have the meaning promulgated by the EPA under
RCRA and that the EPA has the authority to interpret RCRA to decide
whether NHSMs are solids wastes or not.\32\ The agency notes that it
has carefully considered the CAA section 112(b) and 129(a)(4) lists of
pollutants and removed those constituents that would not be appropriate
to evaluate in NHSMs.
---------------------------------------------------------------------------

    \31\ See 76 FR 15524-15525. See also, 75 FR 31883.
    \32\ See 76 FR 15469-15470. See also, 76 FR 15473.
---------------------------------------------------------------------------

    Second, the commenters base their proposed approach to defining
contaminants purely on emissions. The agency agrees that emissions may
be a means of discard but contaminants that are destroyed by the
combustion process or incorporated into products may not have emission
standards established under CAA section 129. Combustion may still be a
means of discard in these instances. Thus, a definition of contaminants
based only on the CAA section 129 emissions standards only tells one
how well the combustion unit is operating, not whether the NHSM is
being used as a legitimate non-waste commodity.\33\
---------------------------------------------------------------------------

    \33\ See 76 FR 15525.
---------------------------------------------------------------------------

    Comment: Several commenters addressed the specific constituents
proposed to be removed from the definition of contaminants. In general,
comments were supportive of the concept that constituents unlikely to
be found in NHSMs prior to combustion or adequately measured elsewhere
in the definition should be removed from the definition.
    Multiple commenters asked that CO also be removed from the
definition because it is unlikely to be found in NHSMs. The same
commenters asked that opacity be removed from the definition because it
can only be measured in emissions and is not directly related to any
one specific constituent in NHSMs. Particulate matter and coke oven
emissions were removed, noted the commenters, because they are products
of combustion unlikely to exist in NHSMs

prior to combustion, and the same can be said for CO and opacity.
    One commenter expressed concern that asbestos had been removed from
the list due to the removal of ``fine mineral fibers'' as a
contaminant. The commenter explained that asbestos is commonly found in
construction and demolition debris and asbestos particles in smoke are
deadly. Excluding fine mineral fibers from regulation explicitly
ignores the possibility of such contamination in C&D debris, noted the
commenter, and asbestos should be a regulated contaminant.
    Response: The EPA has issued a final rule containing the language
removing constituents from the definition of contaminants as proposed,
with one change. The agency has removed ``opacity'' from the final
definition of contaminants as well. Similar to PM and coke oven
emissions, there is no practical way to measure opacity in NHSMs prior
to combustion or in products made using NHSMs. In fact, the EPA did not
intend for opacity to be included in the definition of contaminant
under the previous definition. A visual property of an emissions
stream, opacity is not even a constituent, let alone a constituent that
can be measured in NHSMs prior to combustion or in products made using
NHSMs. As such, removing it from the definition will provide clarity
without effecting any practical change to the definition.\34\
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    \34\ Neither Table 7 nor Table 8 in the December 2011 proposed
rule included opacity. See 76 FR 80478-80480.
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    The agency has not removed CO from the definition of contaminants
because, contrary to comments that it is unlikely to be found in any
NHSM, it is likely to be present in gaseous NHSMs and is not adequately
measured elsewhere in the ``contaminants'' definition. However, as we
discuss in the December 2011 proposed rule, CO is unlikely to be found
in solid or liquid NHSMs and EPA expects that persons can use process
knowledge to justify not testing for CO in these cases.\35\
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    \35\ See 76 FR 80475.
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    The agency has removed the fine mineral fibers group from the
definition of contaminants, as proposed, because they are not expected
to be found in NHSMs. Fine mineral fibers, as regulated under CAA
section 112(b) are releases from the manufacturing and processing of
non-combustible rock, glass or slag into mineral fibers and are not
produced during the combustion process. Asbestos, on the other hand,
has been set apart from the fine mineral fibers group in CAA section
112(b), and thus, it is set apart in the NHSM rule. To be clear,
asbestos is included in the definition of contaminants in today's final
rule and it would be a contaminant regardless of whether the fine
mineral fibers group was removed or not. In summary, the following 12
CAA section 112(b) and section 129(a)(4) pollutants have been removed
from the definition of contaminants: HCl, Cl2, HF,
NOX, SO2, fine mineral fibers, PM, coke oven
emissions, opacity, diazomethane, white phosphorus and titanium
tetrachloride.
c. Established Tire Collection Programs
    The 40 CFR 241.2 definition for ``established tire collection
program,'' as established by the March 2011 promulgation in the Federal
Register, was as follows: ``Established tire collection program means a
comprehensive collection system that ensures scrap tires are not
discarded and are handled as valuable commodities in accordance with
section 241.3(b)(2)(i) from the point of removal from the vehicle
through arrival at the combustion facility.''
    In the December 2011, NHSM proposed rule, the EPA proposed to
revise this definition (and the related criteria for non-waste tires
now at 40 CFR 241.4(a)(1)) in order to account for off-specification
tires. The term ``off-specification tires'' is intended to also include
``factory scraps.'' The off-specification tires are not removed from
vehicles and are handled under contractual arrangements which ensure
they are not discarded. The definition was modified to include
``contractual arrangement'' to provide that not only ``collection
systems,'' but also contractual arrangements for tire collection would
be appropriate. The requirement for the tires to be removed from the
vehicle was eliminated \36\ since it is not applicable to off-
specification tires. The revised definition is sufficient to encompass
the agency's intent in describing these programs and continues to
ensure that these scrap tires are not discarded and are handled as
valuable commodities through arrival at the combustion facility.
Further, the addition to the new categorical non-waste provision at 40
CFR 241.4(a)(1) eliminated the need for the previous scrap tire
provision at 40 CFR 241.3(b)(2)(i),\37\ (which has been removed and
reserved in today's final rule) therefore, the reference to that
provision was removed in the definition. The agency proposed to revise
the definition as follows: ``Established tire collection program means
a comprehensive collection system or contractual arrangement that
ensures scrap tires are not discarded and are handled as valuable
commodities through arrival at the combustion facility.''
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    \36\ The related tire provision at 241.4(a)(1) allows for tires
that are off-specification or are removed from vehicles.
    \37\ The scrap tire provision in the 2011 NHSM final rule is now
removed and the section reserved in today's final rule: ``(b) The
following non-hazardous secondary materials are not solid wastes
when combusted:
     (2) The following non-hazardous secondary materials that have
not been discarded and meet the legitimacy criteria specified in
paragraph (d)(1) of this section when used in a combustion unit (by
the generator or outside the control of the generator):
    (i) Scrap tires used in a combustion unit that are removed from
vehicles and managed under the oversight of established tire
collection programs.''
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    The definition in today's final rule includes the revisions to the
definition we proposed in December 2011. In addition, the agency is
including in the definition ``tires that were not abandoned and were
received from the general public at collection program events.'' This
revision is being made based on comments received on the proposed rule
as discussed below. Under today's revised definition, established tire
collection programs could also include a ``contractual arrangement.''
If, for example, the state is sponsoring special events where they take
tires back from the general public, those tires would also be included.
Thus, the definition in today's final rule is ``Established tire
collection program means a comprehensive collection system or
contractual arrangement that ensures scrap tires are not discarded and
are handled as valuable commodities through arrival at the combustion
facility. This can include tires that were not abandoned and were
received from the general public at collection program events.''
    While the agency did receive comments on the specific proposed
changes described above, a number of commenters rephrased or restated
previous arguments which conclude that any tires burned for energy
recovery are not wastes, even if previously discarded. Conversely, one
commenter reiterated its previous arguments which conclude that all
used tires are waste, even if burned for energy recovery. Today's rule
is responding only to the specific proposed revisions to the
regulations and the requests for comment in the proposal. For the
response to other issues, refer to the record for the 2011 NHSM final
rule (76 FR 15456). Many of the commenters who provided comments on
tires intertwined the ``established tire collection program''
definition issues

with the related topic of the categorical non-waste provision for scrap
tires. For a discussion of those comments, refer to the response to
comments for the categorical non-waste provision for scrap tires
(section III.D.3.a.). The EPA is not reopening its decision that these
scrap tires are not wastes. That decision, however, justifies a
categorical exclusion where there is not a need to make case-by-case
determinations regarding discard in the first instance and the
legitimacy criteria.
    Comment: Several commenters mentioned that, in some cases, the
public individually takes tires to state-run tire collection program
events. These are tires that the general public owns and were typically
removed from their vehicle. These are not abandoned tires. These
collection events, in some cases, are held by the combustor under the
state's environmental program oversight. In those cases, the combustors
enter into agreements with local communities to hold these events
during which local residents are allowed to bring tires to facilities
to be recycled, including used as alternative fuels. The scope of tire
collection programs also may allow the public to take used tires which
they may have stored in their garages, or elsewhere on their property,
directly to a combustion facility--in many cases a cement kiln.
    Under the EPA's current definition of tire collection programs, the
commenters said it is not clear whether these tires would qualify as
those collected under an ``established tire collection program.''
Commenters generally agreed that these tires are not abandoned and
should be utilized as non-waste fuels without processing.
    Response: The EPA agrees with the commenters that tires that have
not been discarded and are collected directly from the public at tire
collection events are intended to qualify for the 40 CFR 241.4(a)(1)
requirement to be ``managed under the oversight of established tire
collection programs.'' The agency agrees that these tires are not
abandoned and when collected under established tire collection program
events, they are considered to be non-waste fuels, just as the other
tires handled by established tire collection programs are non-waste. To
make this point clear, the EPA has modified the regulatory language.
Please refer to the Response to Comment document for more details on
these collection events and the responses.
2. Contaminant Legitimacy Criterion for NHSMs Used as Fuels
    Under the December 2011 proposed rule, revisions to the contaminant
legitimacy criterion for NHSMs used as fuel provided details on how
contaminant comparisons could be made in practice. The proposal
maintained the fundamental approach of the March 2011 final rule, but
the proposed criterion better reflected the EPA's intent to allow
certain flexibilities when making contaminant comparisons.
    First, the proposal replaced ``contaminants'' with the phrase
``contaminants or groups of contaminants'' to clarify that, when
deciding how to compare contaminants between NHSMs and traditional
fuels, persons do not have to make comparisons on a contaminant-by-
contaminant basis in all cases. When technically reasonable,
comparisons may be made on a group of contaminants-by-group of
contaminants basis.
    The December 2011 rule also proposed to codify language from the
preamble to the March 2011 final rule clarifying that when selecting
which traditional fuel(s) a unit is designed to burn, persons are not
limited to the traditional fuel the unit is currently permitted to
burn. Persons may choose any traditional fuel the unit can burn or does
burn, whether or not it is permitted to burn such fuel.
    In addition, the proposed regulations included text confirming
that, when comparing contaminant levels between NHSMs and traditional
fuels, persons are not limited to data from the specific traditional
fuel being replaced. National surveys of traditional fuel contaminant
levels are one example of another acceptable data source. Neither the
March 2011 final rule nor the December 2011 proposed rule required
persons to compare contaminants in their NHSM to contaminants in the
specific traditional fuel source they burn (or would otherwise burn).
As an example, the proposal noted that persons who would otherwise burn
coal may use any as-burned coal available in coal markets in making a
comparison between the contaminants in their NHSM and the contaminants
in coal--they are not limited to coal from a specific coal supplier
they have used in the past or currently use.
    Finally, the proposed regulations included text confirming that,
when comparing contaminant levels between NHSMs and traditional fuels,
persons are not limited to comparing average concentrations.
Traditional fuel contaminant levels can vary considerably and the full
range of contaminant values may be used.
    Two other issues arose prior to the December 2011 proposed rule
that, while not leading to specific regulatory changes in the proposal,
still merited a discussion in the proposal. The first issue was that
contaminant legitimacy criterion determinations do not require testing
contaminant levels, in either the NHSM or an appropriate traditional
fuel. Persons can use expert or process knowledge to justify decisions
to either rule out certain constituents or determine that the NHSM
meets the contaminant legitimacy criterion. The second issue was that
persons may use data from a group of similar traditional fuels for
contaminant comparisons, provided the unit could burn each traditional
fuel. The idea grows from the ``designed to burn'' concept explained in
the March 2011 final rule and codified in today's final rule, and it
allows a person with a unit that can or does burn similar traditional
fuels (e.g., anthracite, lignite, bituminous and sub-bituminous coal)
to group those traditional fuels when making contaminant comparisons.
    The EPA believes that comments have not changed the basis for
making the decisions to expressly allow grouping of contaminants, to
interpret ``designed to burn'' to mean can burn or does burn regardless
of permit status, and to affirm that persons can use ranges and
national surveys of traditional fuel data when making contaminant
comparisons between NHSMs and traditional fuels. Comments have also not
changed the agency's basis for making the decisions that testing is not
required and that persons can group similar traditional fuels for the
purposes of contaminant comparisons. Thus, the EPA is adopting the
reasoning from the proposal and revising the contaminant legitimacy
criterion for NHSMs used as a fuel to incorporate these concepts.
    The EPA has decided, however, to make one modification to the
proposed contaminant legitimacy criterion based on comments received
and information in the rulemaking record. The final criterion issued
today includes additional language clarifying the appropriate use of
ranges when making contaminant comparisons between NHSMs and
traditional fuels. To use the full range of contaminant values in
traditional fuels, persons should also account for the variability in
NHSM contaminant levels.
    Additional details and rationale for the proposed revisions
concerning the grouping of contaminants, the meaning of designed to
burn, and the use of ranges and traditional fuel data in making
contaminant comparisons are discussed in section III.D.2.b, section
III.D.2.c, and section III.D.2.d below. Additional reasoning for
keeping the rule provisions as proposed and for any modifications to
the proposed language

are described in the responses to comments included in these sections.
a. General Comments on the Revised Contaminant Legitimacy Criterion
    The EPA is not responding to issues that the agency decided in the
March 2011 rule and has not reopened for comment. Specifically, the
agency has previously discussed and did not solicit comments in this
rule on why the concept of legitimacy is important in determining
whether a secondary material is genuinely recycled or is, in fact,
discarded.\38\ The agency has also previously discussed and did not
solicit comments in this rule on why contaminant comparisons to
traditional fuels are an appropriate and mandatory factor in
determining legitimacy for NHSMs used as fuels in combustion units.\39\
The agency has also previously discussed and did not solicit comments
in this rule on why the ``comparable to or lower than'' standard is
more appropriate than the ``not significantly higher than''
standard.\40\ The agency has also previously discussed that the NHSM
Rule differs from the DSW Rule in that it is tailored specifically for
application to NHSMs used in combustion units.\41\
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    \38\ See 75 FR 31870.
    \39\ See 75 FR 31871-31872. See also, 76 FR 15524-15525.
    \40\ See 75 FR 31872. See also, 76 FR 15523.
    \41\ See 75 FR 31870.
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    Comment: Industry commenters overwhelmingly supported the proposed
revisions to the contaminant legitimacy criterion, stating that the
revisions would help provide regulatory certainty and give the
regulated community more confidence in their self-determinations.
    Environmental groups, on the other hand, expressed concern that the
combination of flexibilities present in the proposed revisions to the
contaminant legitimacy criterion will allow facilities to compare
contaminant levels in C&D debris and other wood waste to the highest
contaminant levels found in coal, even if the facility is not permitted
to burn coal. They believed that this should not be permitted and
argued that C&D wood should not contain contaminant levels higher than
found on average in virgin biomass.
    State comments were mixed, with one commenter supporting the
proposed revisions and another commenter expressing concern that the
revisions would weaken the states' permitting authorities and create an
incentive for combustors to burn dirtier traditional fuels.
    Response: The EPA has decided to retain the concepts proposed to
the contaminant legitimacy criterion because these changes more
accurately reflect the EPA's intent under the March 2011 final rule.
The agency maintains that these concepts are reasonable and provide a
necessary degree of certainty for persons seeking to comply with the
rule. This is explained in more detail in sections III.D.2.b (groups of
contaminants), III.D.2.c (meaning of designed to burn), and III.D.2.d
(allowable contaminant comparisons) of this preamble.
    At the same time, comments from both industry and environmental
groups have highlighted, in the agency's opinion, a need for additional
clarity in the regulatory text on the appropriate use of ranges when
making contaminant comparisons between NHSMs and traditional fuels.
Accordingly, the EPA has made a minor adjustment to the criterion to
ensure that ranges are not used inappropriately in contaminant
comparisons (i.e., the highest traditional fuel contaminant values
should not be compared to average NHSM contaminant values). See section
III.D.2.d of this preamble for a more detailed description of this
specific change to the contaminant legitimacy criterion.
    The agency disagrees with state concerns that the NHSM rule will
weaken the states' permitting authorities. State permitting authorities
must still approve permit changes and this final rule does not affect
discretion of the permitting authorities in acting on requests for
permit modifications. The agency also disagrees with state concerns
that the NHSM rule will create an incentive for combustors to burn
dirtier traditional fuels. The EPA understands how restricting
contaminant comparisons to traditional fuels the unit currently burns
could provide an incentive for the facility to burn traditional fuel
with high contaminant levels. When facilities do not actually have to
burn that traditional fuel to make comparisons, however, that incentive
is effectively removed.
    Comment: One commenter requested that the proposed revisions to the