Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Medical Waste Incinerators
Federal RegisterJun 20, 1996
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SUMMARY: On February 27, 1995, EPA proposed new source performance
standards (NSPS or standards) and emission guidelines (EG or
guidelines) for new and existing medical waste incinerator(s) (MWI)
that will reduce air pollution from MWI. Once implemented, these
standards and guidelines will protect public health by reducing
exposure to air pollution. In the proposal preamble, EPA made a
commitment to reconsider the proposed NSPS and EG based on new
information submitted. Today's action presents an assessment of the
supplemental information submitted following the proposal and solicits
public comment on this assessment. Today's action also serves to
address comments received on the proposal and reopens the comment
period for development of the MWI standards and guidelines.
DATES: Public Meeting. A public meeting will be held on July 10, 1996
beginning at 9:00 a.m. At the public meeting, EPA will review the
contents of this notice and answer questions so that commenters can
better prepare their written comments. See ADDRESSES below for the
location of the meeting.
Comments. Comments are requested on all information associated
with the development of MWI standards and guidelines. Written comments
must be received on or before August 8, 1996. See ADDRESSES below.
ADDRESSES: Public Meeting. The public meeting will take place at the
Holiday Inn, Hotel and Suites, 625 First Street, Alexandria, Virginia,
22314, (703) 548-6300. Persons interested in attending the meeting
should notify Ms. Donna Collins, U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, telephone (919) 541-5578.
Comments. Comments should be submitted (in duplicate, if possible)
to the following: The Air and Radiation Docket and Information Center,
ATTN: Docket No. A-91-61, U.S. Environmental Protection Agency, 401 M
Street, SW, Washington, DC 20460.
Submissions containing proprietary information (Confidential
Business Information) should be sent directly to the following address,
not to the public docket, to ensure that proprietary information is not
inadvertently placed in the docket: Attention: Mr. Rick Copland, c/o
Ms. Melva Toomer, U.S. Environmental Protection Agency Confidential
Business Manager, 411 W. Chapel Hill Street, Room 944, Durham, North
Carolina 27701. See SUPPLEMENTARY INFORMATION for further discussion of
confidential business information.
Docket. Docket No. A-91-61, containing supporting information used
in developing the standards and guidelines, is available for public
inspection and copying between 8:00 a.m. and 4:00 p.m. , Monday through
Friday, at the Air and Radiation Docket and Information Center, U.S.
Environmental Protection Agency, 401 M Street, SW, Washington, DC
20460, telephone (202) 260-7548, fax (202) 260-4000. A reasonable fee
may be charged for copying. See SUPPLEMENTARY INFORMATION for a list of
documents most directly related to today's notice.
FOR FURTHER INFORMATION CONTACT: Mr. Rick Copland at (919) 541-5265 or
Mr. Fred Porter at (919) 541-5251, Emission Standards Division (MD-13),
U.S. Environmental Protection Agency, Research Triangle Park, North
Carolina 27711.
SUPPLEMENTARY INFORMATION: Regulated Entities. Entities potentially
regulated by the standards and guidelines are those which operate
medical waste incinerators. Regulated categories and entities include
those listed in Table 1.
Table 1.--Regulated Entities a
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Category Examples of regulated entities
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Industry.................................................... Hospitals, nursing homes, research laboratories,
other healthcare facilities, commercial waste
disposal companies.
Federal Government.......................................... Armed services, public health service, Federal
hospitals, other Federal healthcare facilities.
State/local/Tribal Government............................... State/county/city hospitals and other healthcare
facilities.
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a This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely
to be regulated by the standards or guidelines for MWI. This table lists the types of entities that EPA is now
aware could potentially be regulated. Other types of entities not listed in the table could also be regulated.
To determine whether your facility is regulated by the standards or guidelines for medical waste incinerators,
you should carefully examine the applicability criteria in sections 60.50(c) and 60.51(c) of the February 1995
proposal and sections II(B), II(H), and II(I) of today's notice. If you have questions regarding the
applicability of the MWI standards and guidelines to a particular entity, consult the person listed in the
preceding FOR FURTHER INFORMATION CONTACT section.
Confidential Business Information. Commenters wishing to submit
proprietary information for consideration should clearly distinguish
such information from other comments and clearly label it
``Confidential Business Information.'' Information covered by such a
claim of confidentiality will be disclosed by the EPA only to the
extent allowed and by the procedures set forth in 40 CFR part 2. If no
claim of confidentiality accompanies a submission when it is received,
the submission may be made available to the public without further
notice to the commenter.
Documents Available Electronically. An electronic version of this
action as well as the February 1995 Federal Register proposal notice
are available for download from EPA's Technology Transfer Network
(TTN), which is a network of electronic bulletin boards developed and
operated by EPA's Office of Air Quality Planning and Standards. The TTN
provides information and technology exchange in various areas of air
pollution control. The service is free, except for the cost of a
telephone call. Dial (919) 541-5742 for data transfer of up to 14,400
bits per second. The TTN is also available on the Internet (access:
TELNET ttnbbs.rtpnc.epa.gov). For more information on the TTN, contact
the systems operator at (919) 541-5384.
Documents in the Docket. The documents listed below are not
available through the TTN, but are available through Air Docket No. A-
91-61 located at the Air and Radiation Docket and Information Center
(see the ADDRESSES section earlier in this
[[Page 31737]]
notice). These documents provide the analyses that are summarized in
this notice.
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Item No. Title
------------------------------------------------------------------------
IV-A-7................... National Dioxin Emission Estimates from
Medical Waste Incinerators.
IV-A-8................... Revised Economic Impacts: Existing Medical
Waste Incinerators.
IV-A-9................... Revised Economic Impacts: New Medical Waste
Incinerators.
IV-B-23.................. PM MACT Floor Emission Levels for Potential
Subcategories of the MWI Source Category.
IV-B-24.................. Determination of the Maximum Achievable
Control Technology (MACT) Floor for Existing
Medical Waste Incinerators that Incinerate
General Medical Waste.
IV-B-25.................. Definition of Medical Waste.
IV-B-26.................. Operator Training and Qualification and
Incinerator Inspection Requirements.
IV-B-30.................. Approach Used to Estimate the Capital and
Annual Costs for MWI Wet Scrubbers.
IV-B-32.................. Revised Costs for Dry Injection/Fabric Filter
Controls for MWI.
IV-B-33.................. Revised Costs for Secondary Chamber Retrofits
for MWI.
IV-B-37.................. Projections for New MWI Population.
IV-B-38.................. Determination of the Maximum Achievable
Control Technology (MACT) Floor for New
Medical Waste Incinerators.
IV-B-39.................. Annual Costs for the Operator Training and
Qualification Requirements for MWI
Operators.
IV-B-43.................. Alternative Methods of Medical Waste
Treatment: Availability, Efficacy, Cost,
State Acceptance, Owner Satisfaction,
Operator Safety, and Environmental Impacts.
IV-B-44.................. Determination of Medical Waste Incinerator
(MWI) Size.
IV-B-45.................. Updated Medical Waste Incinerator Data Base.
IV-B-46.................. PM, CO, and CDD/CDF Average Emission Rates
and Achievable Emission Levels for MWI with
Combustion Controls.
IV-B-47.................. Acid Gases and Metals Typical Performance and
Achievable Emission Levels for Medical Waste
Incinerators with Good Combustion Control.
IV-B-48.................. Wet Scrubber Performance Memorandum.
IV-B-49.................. Dry Scrubber Performance Memorandum.
IV-B-50.................. Cost Impacts of the Regulatory Options for
New and Existing Medical Waste Incinerator
(MWI).
IV-B-51.................. Air Emission Impacts of the Regulatory
Options for New and Existing Medical Waste
Incinerators (MWI).
IV-B-52.................. Potential Solid Waste, Wastewater, and Energy
Impacts of the New Source Performance
Standards and Emission Guidelines for New
and Existing Medical Waste Incinerators.
IV-B-54.................. Testing and Monitoring Options and Costs for
MWI--Methodology and Assumptions.
IV-B-56.................. Standards of Performance for Medical Waste
Pyrolysis Units.
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Acronyms, Abbreviations, and Measurement Units. The following list
of acronyms, abbreviations, and measurement units is provided to aid
the reader.
AHA................................. American Hospital Association
Btu................................. British thermal unit
Cd.................................. cadmium
CEMS................................ continuous emission monitoring
system(s)
CFR................................. Code of Federal Regulations
CO.................................. carbon monoxide
dioxin.............................. dioxins and dibenzofurans
DI/FF............................... dry injection/fabric filter
dscf................................ dry standard cubic foot
dscm................................ dry standard cubic meter
EG.................................. emission guidelines
EPA................................. Environmental Protection Agency
ft3................................. cubic feet
FTE................................. full time equivalent
g................................... grams
gr.................................. grains
HCl................................. hydrogen chloride
Hg.................................. mercury
hr.................................. hour
IV.................................. intravenous
lb.................................. pound
MACT................................ maximum achievable control
technology
m3.................................. cubic meter
MW.................................. megawatt
MSA................................. Metropolitan Statistical Area
Mg.................................. megagram
mg.................................. milligram
MM.................................. million
MWI................................. medical waste incinerator(s)
MWTA................................ Medical Waste Tracking Act
MWC................................. municipal waste combustor
ng.................................. nanogram
NOX................................. Oxides of nitrogen
NRDC Natural Resources Defense Council
NSPS................................ new source performance standards
NYSDOH.............................. New York State Department of
Health
O2.................................. oxygen
Pb.................................. lead
PM.................................. particulate matter
ppmdv............................... parts per million by volume (dry
basis)
SO2................................. sulfur dioxide
STAATT.............................. State and Territorial Association
of Alternate Treatment
Technologies
SWDA................................ Solid Waste Disposal Act
TEQ................................. Toxic Equivalency Quality (dioxin
emissions)
TTN................................. Technology Transfer Network
TCLP................................ Toxicity Characteristics Leachate
Procedure
yr.................................. year
Outline of this Notice. The information in this section is
organized as follows:
I. Introduction
A. The Clean Air Act
B. February 1995 Proposal
C. New Information Since Proposal
D. Purpose of this Supplemental Notice
E. New Timeline for Promulgation
II. Review of New Information
A. MWI Inventory
1. Existing Population
2. Future Installations
B. Subcategorization
C. Performance and Cost of Technology
1. Good combustion
2. Wet scrubbers
3. Dry scrubbers
D. MACT Floor
1. Existing MWI
2. New MWI
E. Baseline Emissions
F. Operator Training and Qualification
G. Testing, Monitoring, and Inspection
H. Definition of Medical Waste
I. Pyrolysis Units
J. Alternative Medical Waste Treatment Technologies
III. Regulatory Options and Impacts for Existing MWI
A. Regulatory Options
B. National Environmental and Cost Impacts
1. Analytical approach
2. Air Impacts
3. Water and solid waste impacts
4. Energy Impacts
5. Cost Impacts
C. Economic Impacts
1. Analytical approach
2. Industry-wide economic impacts
3. Facility-specific economic impacts
IV. Regulatory Options and Impacts for New MWI
A. Regulatory Options
B. National Environmental and Cost Impacts
1. Analytical approach
2. Air impacts
3. Water and solid waste impacts
[[Page 31738]]
4. Energy Impacts
5. Cost Impacts
C. Economic Impacts
1. Analytical approach
2. Industry-wide economic impacts
3. Facility-specific economic impacts
V. Inclinations for Final Rule
I. Introduction
A. The Clean Air Act
The Clean Air Act amendments of 1990 added section 129, which
includes specific requirements for solid waste combustion units.
Section 129 requires the EPA, under section 111(b), to establish NSPS
for new MWI and under section 111(d), to establish EG for existing MWI
based on maximum achievable control technology (MACT). Section 129
establishes specific criteria that must be analyzed in developing these
standards and guidelines. In general, this involves (1) determining
appropriate subcategories within a source category; (2) determining the
``MACT floor'' for each subcategory; (3) assessing available air
pollution control technology with regard to achievable emission
limitations and costs; and (4) examining the cost, nonair-quality
health and environmental impacts, and energy requirements associated
with standards and guidelines more stringent than the MACT floor.
Section 129 also directs EPA to establish operator training
requirements for new and existing MWI as well as siting requirements
for new MWI.
Section 129 requires the EPA to include numerical emission
limitations in the standards and guidelines for the following air
pollutants: particulate matter (PM), opacity, sulfur dioxide
(SO2), hydrogen chloride (HCl), oxides of nitrogen (NOx),
carbon monoxide (CO), lead (Pb), cadmium (Cd), mercury (Hg), and
dioxins and dibenzofurans (referred to in this notice as ``dioxin'').
Section 129 requires that these emission limitations reflect the
maximum degree of reduction in air emissions that the Administrator
determines is achievable, taking into consideration the cost of
achieving such emission reduction and any nonair-quality health and
environmental impacts and energy requirements. This requirement is
referred to as MACT.
The MACT for new MWI may not be less stringent than the emissions
control achieved in practice by the best controlled similar unit. The
guidelines for existing MWI may be less stringent than the standards
for new MWI; however, the guidelines may be no less stringent than the
average emission limitation achieved by the best performing 12 percent
of units in the category. These requirements that the standards and
guidelines must be no less stringent than certain levels are referred
to as the ``MACT floor.''
The Clean Air Act requires EPA to consider standards and guidelines
more stringent than the MACT floor, considering costs and other impacts
described above. If EPA concludes that more stringent standards and/or
guidelines are achievable considering costs and other impacts, then the
standards and/or guidelines would be established at these more
stringent levels (i.e., MACT would be more stringent than the MACT
floor). The EPA may establish NSPS or EG at the MACT floor only if it
concludes that NSPS or EG more stringent than the MACT floor are not
achievable, considering costs and other impacts. In no case may EPA
establish emission limitations less stringent than the MACT floor.
Because standards and guidelines developed under Section 129 are to
reflect the performance capabilities of air pollution control
technology, EPA must assess air pollution control technologies and draw
conclusions regarding their performance. This is often misunderstood
and some assume that the regulations require the use of specific
technology. However, the control technology used to achieve the
standards or guidelines is not specified in the regulations. The
regulations only include specific air pollution emission limits that a
source (i.e., an MWI) must achieve. Any control technology that can
comply with the final emission limits may be used.
B. February 1995 Proposal
On February 27, 1995 (60 FR 10654), EPA published proposed NSPS and
EG for MWI. The proposal was the result of several years of effort
reviewing available information in light of the Clean Air Act
requirements described above.
During the data-gathering phase of the project, it was difficult to
get an accurate count of MWI nationwide. In addition, it was difficult
to find MWI with add-on air pollution control systems in place.
Information from a few State surveys led to an estimated population of
3,700 existing MWI.
Subcategories were determined based on design differences among
different types of incinerators: continuous, intermittent, and batch.
These three design types roughly correlate to MWI size.
A few MWI with various levels of combustion control (no add-on air
pollution control) were tested to determine the performance of
combustion control in reducing MWI emissions. One MWI equipped with a
wet scrubber (add-on control) was tested to determine the performance
capabilities of wet scrubbing systems. A few other MWI equipped with
dry scrubbing systems (add-on control) were tested to determine the
performance capabilities of dry scrubbing systems. These systems were
considered typical of air pollution control systems available at the
time, and the data indicated that dry scrubbing systems could achieve
much lower emissions than wet scrubbing systems.
As mentioned above, the MACT floor for new MWI is to reflect the
emissions control achieved by the best controlled similar unit. Dry
scrubbing systems were identified on at least one MWI in each of the
three subcategories (continuous, intermittent, and batch).
Consequently, the MACT floor emission levels for the proposed NSPS
reflected the performance capabilities of dry scrubbing systems.
For existing MWI under the emission guidelines, State regulations
and permits were used to calculate the average emission limitation
achieved by the best performing 12 percent of units. These results were
then compared with the results of the emission tests on wet and dry
scrubbing systems. This comparison led to the conclusion that the MACT
floor for existing MWI would require the use of a dry scrubbing system,
even for small existing batch MWI.
Following determination of the MWI population, subcategories,
performance of technology, and MACT floors, the Clean Air Act requires
EPA to consider standards and guidelines that are more stringent than
the floors. However, because the MACT floors calculated for the
proposal were so stringent, EPA was left with few options to consider.
Emission limits reflecting the capability of dry scrubbing systems were
proposed for all sizes and types of new and existing MWI.
As mentioned earlier, the proposed standards and guidelines
included numerical emission limits reflecting the performance
capabilities of dry scrubbing systems; however, the proposed
regulations would not require the use of a dry scrubbing system.
Emission limits are included in these regulations rather than control
equipment requirements to encourage competition and further the
development of new technologies. Any technology capable of achieving
the emission limitations in the regulations may be used.
[[Page 31739]]
C. New Information Since Proposal
A proposal is essentially a request for public comment on the
information used, assumptions made, and conclusions drawn from the
evaluation of available information. Following proposal, more than 700
comment letters were received, some including new information and some
indicating that commenters were in the process of gathering information
for EPA to consider. The large amount of new information that was
ultimately submitted addressed every aspect of the proposed standards
and guidelines, including: the existing population of MWI, the
performance capabilities of air pollution control systems, monitoring
and testing, operator training, alternative medical waste treatment
technologies, and the definition of medical waste. In almost every
case, the new information has led to different conclusions, as outlined
below.
D. Purpose of This Supplemental Notice
This notice announces the availability of new information, reviews
EPA's assessment of the new information, provides EPA's inclination as
to how the new information might change the final standards and
guidelines, and solicits comments on EPA's assessments and
inclinations. This new information and these assessments are documented
in more detail in a series of memoranda included in Air Docket No. A-
91-61. A listing of these documents can be found at the beginning of
this notice. This action also reopens the public comment period for the
development of standards and guidelines for MWI. Today's action serves
not only as a review of new information and request for comment, but
also as a response to comments on the proposed rule.
This notice is not a reproposal. The proposal date for the MWI
standards and guidelines remains February 27, 1995. Any MWI that has
commenced construction after February 27, 1995, is considered a new MWI
and will be subject to the NSPS, while any MWI that commenced
construction on or before February 27, 1995, is considered an existing
MWI.
E. New Timeline for Promulgation
In 1993, the EPA, the Sierra Club, and the Natural Resources
Defense Council (NRDC) filed a consent decree with the U.S. District
Court for the Eastern District of New York (Nos. CV-92-2093 and CV-93-
0284) that required the EPA Administrator to sign a notice of proposed
rulemaking no later than February 1, 1995 and a notice of final
rulemaking no later than April 15, 1996.
Because of the large amount of new information and conclusions
drawn from the new information, the EPA deemed it necessary to issue
this supplemental Federal Register notice to provide the public
sufficient opportunity to comment on all information used by the Agency
in developing the NSPS and EG. The Agency requested an extension of the
April 15, 1996 court-ordered deadline, and the court order has been
revised to require the EPA Administrator to sign a notice of final
rulemaking no later than July 25, 1997.
II. Review of New Information
As mentioned earlier, more than 700 comment letters were received
following the February 27, 1995 proposal. An assessment of this
information and some of EPA's inclinations in light of this new
information are presented below.
In general, the following process was used to assess the new
information. The public comment letters were reviewed and categorized
by area of comment. Information related to specific issues (e.g., wet
scrubber performance) was reviewed; meetings were then held to discuss
specific areas of comment with relatively small groups who were
believed to have expertise in specific areas. For example, meetings
with wet scrubber vendors were held to discuss the new information
related to the performance capabilities of wet scrubbers. During the
smaller meetings, additional information was received and comment was
taken. Following the smaller meetings, EPA conducted larger public
meetings on June 15, 1995, September 26, 1995, and February 14, 1996,
to review the assessment of new information and take further public
comment. This Federal Register notice provides EPA's review of all
information received since proposal.
A. MWI Inventory
One of the essential starting points in developing EG and NSPS is
compiling an inventory of existing sources and projecting the number of
new sources expected to be built in the future. The MWI inventory is
the basis for the development of MACT floors, environmental impacts,
cost impacts, and economic impacts. The results of these analyses are
then used to determine MACT.
The inventory of existing sources used in this analysis is a
``snapshot'' of the current population of existing MWI. The inventory
of new MWI potentially subject to the NSPS is a prediction of the
number of MWI that will be built over the next 5 years in the absence
of Federal regulations. The MWI inventories are not exact, but are
representative of current and future MWI populations. Consequently,
they are adequate to allow EPA to make informed decisions in developing
standards and guidelines for new and existing MWI.
1. Existing Population
To estimate the nationwide population of existing MWI at proposal,
available State MWI inventory information was gathered. Where MWI
information was not available for a particular State, the State's human
population was used to estimate the MWI population. Human population
was selected as the basis for extrapolation because it is logical that
the amount of medical waste generated (and, therefore, the MWI
population) would correlate with human population. This extrapolation
was a straightforward computation with readily available data; however,
detailed State inventory data were only available from 11 States. This
method resulted in an estimated 3,700 MWI burning general medical
waste.
Following proposal, a number of comments were received regarding
the inventory of existing MWI. Several commenters suggested that the
population of MWI was overestimated. The American Hospital Association
(AHA) submitted comments that included a compilation of approximately
2,200 existing MWI.
To compile a new EPA inventory, the AHA inventory was used as a
starting point. Other sources of information, including State surveys
and a data base of MWI operating permits, were also used to refine the
inventory. Following this initial compilation, the inventory contained
approximately 2,600 MWI. During the September 26, 1995 public meeting,
several stakeholders voiced concern that many of the incinerators
listed in EPA's MWI inventory had ceased operation. To address this
concern, the Agency requested additional information to update the
inventory. Additional information was received from State agencies,
commercial medical waste disposal companies, and MWI vendors. Medical
waste incinerator units were deleted or added based on the new
information provided. Following these revisions, the final EPA
inventory contains approximately 2,400 MWI; this inventory is located
in the docket as item No. IV-B-45.
The inventory also contains information such as MWI type
(continuous/intermittent or batch fed), capacity, and location, as well
as State
[[Page 31740]]
regulatory or permit emission limits. Every MWI in the inventory is
assigned an MWI capacity in pounds per hour (lb/hr) or pounds per batch
(lb/batch). Location information includes rural or urban designations
based on Metropolitan Statistical Area (MSA) boundaries for the U.S.
Facilities within MSA boundaries were considered urban MWI; facilities
outside MSA boundaries were considered rural MWI. Emission limitations
were determined by examining air quality permits, where available, or
examining the emission limitations included in State regulations.
2. Future Installations
Projections of new MWI were made to estimate the costs and other
impacts associated with NSPS. To estimate the number of new MWI that
would be subject to the NSPS, historical sales data were obtained from
MWI vendors. For the proposal, it was estimated that, in the absence of
Federal regulations, 700 MWI would be installed during the 5 years
following proposal (140 MWI per year). This projection was based on
historical sales data gathered from 1985 through 1989.
To update the projection of new MWI that would be subject to the
NSPS, additional data were gathered from MWI vendors following the
proposal. Historical sales data were gathered covering years 1990 to
1995. Based on this new data, 235 MWI are expected to be installed in
the next 5 years in the absence of the NSPS (47 per year). This
projection covers the years 1996 to 2000. The memorandum documenting
the procedures used to estimate the population of new MWI is located in
the docket as item IV-B-37.
B. Subcategorization
Section 129 of the Clean Air Act states that the Administrator may
distinguish among classes, types, and sizes of units within a category
in establishing the standards and guidelines. At proposal, the Agency
concluded the MWI population should be divided into three
subcategories: (1) Continuous MWI, (2) intermittent MWI, and (3) batch
MWI. While these three subcategories were based on design differences
of the MWI, they also correlate roughly with size or MWI capacity.
During the public comment period, a number of comments were
received regarding subcategorization. Several commenters suggested that
EPA subcategorize directly by MWI size. Others suggested that EPA
subcategorize MWI based on heat input capacity. Other commenters
suggested that the Agency set standards based on the location of MWI;
these commenters expressed concern about the lack of medical waste
disposal options in remote rural locations.
Three criteria were subsequently considered in reexamining
potential subcategories: size (capacity to burn medical waste); type
(continuous/intermittent versus batch); and location (urban versus
rural). The first two are clearly identified in Section 129 and have
been used in other Federal regulations as criteria for
subcategorization. Location, by itself, is not a valid criterion for
subcategorization. However, in this case, it is used as a surrogate
measure of the availability of alternative waste disposal options.
Medical waste incinerators located in remote areas might be considered
as a separate ``class'' of incinerator because of the limited
availability of alternative waste disposal options in rural areas.
As mentioned earlier, the MACT floor is the least stringent
regulatory option allowed under the Clean Air Act. Consequently, the
MACT floors were examined using the EPA MWI inventory for various
potential MWI subcategories. Because PM is, by far, the most common
type of emission limitation in State regulations and permits, the PM
MACT floor was the focus in this analysis. Subcategories were
established when significant differences in PM MACT floors were
identified.
The most common size breaks used by States in regulating MWI occur
at 100, 200, 500, 1,000, and 2,000 lb/hr. The MACT floor emission
levels for these size breaks were evaluated to determine appropriate
size breaks for regulation. Significant differences in MACT floors were
identified at 200 lb/hr and 500 lb/hr. Consequently, the three size
ranges determined to be appropriate for the purpose of regulating MWI
are presented in Table 2.
Table 2.--Number of MWI and Size Ranges for Subcategories
------------------------------------------------------------------------
Number
MWI subcategory Size range, lb/hr of MWI
------------------------------------------------------------------------
Small................................ 200.......... 1,139
Medium............................... >200 and 500. 692
Large................................ >500.................... 542
------------------------------------------------------------------------
The three basic design types of MWI are continuous, intermittent,
and batch. A distinction between continuous and intermittent MWI based
on design type may not be appropriate because these two types of units
are essentially identical with the exception of the ash handling
system. Also, the information used to develop the population of
existing MWI does not distinguish between continuous and intermittent
MWI. Batch MWI, however, are very different from intermittent and
continuous units. As a result, batch MWI were further examined to
determine if the MACT floor emission levels are different than those
for continuous and intermittent MWI within the same size range; no
significant difference in MACT floor emission levels was found.
The final criterion considered was location (urban vs. rural). This
analysis focused on the small MWI because commenters were particularly
concerned about small, rural MWI. The MACT floor emission levels for
small urban MWI and small rural MWI, however, were found to be
essentially the same.
Based on the new information, the Agency is inclined to
subcategorize the existing and new population of MWI into three
subcategories as shown in Table 2: small (200 lb/hr), medium
(>200 and 500), and large (>500). The memorandum that
details the procedures used to assess the subcategories is found in the
docket as item IV-B-23. Further subcategorization may be considered in
examining standards and guidelines more stringent than the MACT floors
(see Sections III and IV).
Directly related to the question of using size or burning capacity
to subcategorize MWI, the proposal requested comment on a ``standard''
method of determining MWI size for the purpose of consistent, uniform,
and equitable application of whatever standards and guidelines are
adopted. Comments responding to this request focused on the design heat
release rate of the MWI expressed in British thermal units per hour per
cubic foot (Btu/hr-ft3) in the primary combustion chamber and the
heat content of medical waste expressed in British thermal units per
pound (Btu/lb). Most MWI manufacturers base their design capacities on
these two factors.
In considering and/or adopting a ``standard'' means of determining
MWI size, EPA is not attempting to establish design requirements for
MWI manufacturers. Instead, the only purpose of adopting a standard
method for determining the size of MWI is to ensure that all MWI of the
same ``size'' are subject to the same requirements.
The design heat release rate used by most vendors of continuous and
intermittent MWI is typically 15,000 Btu/hr-ft3. The heat content
of medical waste can vary substantially from 1,000 Btu/lb for
pathological waste to over 10,000 Btu/lb for waste with a high
[[Page 31741]]
plastics content. The heat content generally associated with medical
waste for the purpose of determining nameplate capacity has been 8,500
Btu/lb. The combination of 15,000 Btu/hr-ft3 and 8,500 Btu/lb
results in a volumetric waste burning capacity of 1.76 lb/hr-ft3.
The volume of the primary chamber is multiplied by 1.76 to determine
the size of the MWI. A continuous or intermittent MWI with a primary
chamber volume of 500 ft3 would be sized at 880 lb/hr for the
purpose of determining regulatory requirements.
For batch MWI, the calculation is slightly different. Batch MWI
charge all waste to be burned when the unit is cold. No additional
waste is added during the combustion cycle. The unit is then allowed to
cool before ash is removed and more waste is charged. These units are
given a designation of pounds per batch (lb/batch) rather than lb/hr
and usually take about 12 hours to completely burn the waste. The
density of medical waste is about 4.5 lb/ft3. Consequently, the
combination of 4.5 lb/ft3 and 12 hours per batch yields a
volumetric waste burning capacity of 0.375 lb/hr-ft3. The volume
of the primary chamber would be multiplied by 0.375 to determine the
size of the MWI. A batch MWI with a primary chamber volume of 500
ft3 would be sized at 188 lb/hr for the purpose of determining
regulatory requirements. A more detailed description of the MWI size
methods described above for continuous, intermittent, and batch MWI can
be found in the docket as item IV-B-44.
During a meeting with MWI vendors, it was suggested that MWI size
should be determined by the unit's operating permit rather than its
design capacity. Many States allow MWI to meet less stringent
requirements associated with smaller MWI as long as the MWI is subject
to a permit condition limiting the amount of waste burned.
Consequently, while EPA is inclined to determine MWI size by the
criteria described above, EPA is also considering inclusion of an
option to allow an MWI to change its size designation by operating
under a Federally enforceable requirement limiting the amount of waste
burned (i.e., waste feed rate--lb/hr). For example, a continuous or
intermittent MWI with a 340 ft3 primary chamber, with a design
capacity of about 600 lb/hr (i.e., ``large''), using the procedure
outlined above, could be considered a ``medium'' MWI by operating under
a Federally enforceable requirement limiting its charge rate to no more
than 500 lb/hr. A batch MWI with a 1,000 ft3 primary chamber, with
a design capacity of about 4,500 lb/batch or 375 lb/hr (i.e.,
``medium''), using the procedure outlined above, could be considered a
``small'' MWI by operating under a Federally enforceable requirement
limiting its charge rate to no more than 2,400 lb/batch (200 lb/hr).
Finally, some commenters expressed concern about facilities
installing multiple small MWI at one location in an effort to be
subject to less stringent requirements. Commenters believed this should
not be allowed. Consequently, EPA is inclined to combine the waste
burning capacity of multiple units at one location to determine size.
As stated above, such facilities could still operate under a Federally
enforceable permit limiting their operating capacity to change their
size designation.
C. Performance and Cost of Technology
Section 129 of the Clean Air Act directs the EPA to develop
regulations for MWI that are based on the use of MACT, which is defined
as the maximum reduction in emissions of air pollution the EPA
considers achievable, considering costs, environmental, and energy
impacts. However, Section 129 also states that, for existing MWI, these
regulations can be no less stringent than the average of the best 12
percent of existing MWI, and for new MWI, they can be no less stringent
than the best similar MWI. These minimum stringency requirements for
the regulations are referred to as the ``MACT floors.'' The emission
limits in the final regulations can be no less stringent than the
``MACT floor'' emission levels.
The ``MACT floors'' for the regulations are discussed in detail in
another section of this notice. However, these ``MACT floors'' are only
the starting point for determining MACT. Since MACT is the maximum
reduction in air pollution emissions that is achievable, considering
costs, environ-mental and energy impacts, if more stringent emission
levels than the MACT floor emission levels are achievable, the EPA must
identify these more stringent emission levels and consider them in
selecting the MACT emission limits for MWI.
The EPA determines whether more stringent emission levels than the
MACT floor emission levels are achievable by identifying various air
pollution control technologies used to reduce emissions from MWI. Next,
the EPA gathers and analyzes data on these technologies and draws
conclusions regarding their performance--in terms of their ability to
reduce air pollution emissions. The EPA then is able to determine MACT
as follows.
After the MACT floors have been determined, the EPA can identify
what air pollution control technologies would need to be used by MWI to
achieve or comply with regulations based on these MACT floors. Then the
EPA can identify those air pollution control technologies that are
capable of achieving more stringent emission levels than the MACT
floors. The EPA is then able to analyze and consider these more
stringent emission levels in terms of the cost, environmental, and
energy impacts associated with their use compared to the use of the air
pollution control technologies that can achieve the MACT floor emission
levels. This analysis and consideration serves as the basis for the EPA
to determine MACT.
All of this analysis, with its focus and discussion of air
pollution control technology, is often misunderstood and leads some to
assume that the regulations require the use of a specific air pollution
control technology, which is not the case. The air pollution control
technology used to achieve or comply with the regulations is not
specified in the regulations. The regulations only include emission
limits (i.e., concentration levels in the gases released to the
atmosphere) for specific air pollutants (e.g., hydrogen chloride, lead,
etc.) that an MWI must achieve. The decision on how to meet these
emission limits is left to the MWI owner or operator; an MWI owner or
operator may select any equipment or any means available to comply with
these emission limits.
At the time of proposal, relatively few emission test reports were
available to the EPA from which to draw conclusions regarding the
performance capabilities of various air pollution control systems. The
data indicated that dry scrubbing systems could achieve much lower
emission levels than wet scrubbing systems and that either type of
scrubbing system could achieve much lower emission levels than
combustion controls (i.e., good combustion) alone.
Following proposal, a number of emission test reports were
submitted to EPA. Many commenters believe that EPA misjudged the
performance capabilities of various air pollution control technologies,
especially the capabilities of wet scrubbing systems. The EPA has
reviewed the data contained in these emission test reports and, as
summarized below, EPA's conclusions regarding the performance
capabilities of various air pollution control technologies have been
revised.
Relatively few comments were received regarding EPA's estimates of
the costs of air pollution control technology. The majority of the
[[Page 31742]]
comments regarding cost pertained to wet scrubbing systems. The
reassessment of costs is discussed briefly below for each control
technology.
1. Good Combustion
Combustion controls (i.e., good combustion) are effective in
reducing emissions of combustion-related pollutants, such as PM, CO,
and dioxin, but are not effective in reducing emissions of waste-
related pollutants, such as acid gases or metals. For the combustion-
related pollutants, combustion controls can be divided into two levels
(i.e., 1-second and 2-second residence time) and the achievable
emission levels associated with the use of each of these levels have
been reassessed. In addition, achievable emission levels for waste-
related pollutants were also reassessed. For waste-related pollutants,
performance between the two levels of combustion control is not
distinguishable. The results of the reassessment of combustion control
are shown in Table 3 and are available as item Nos. IV-B-46 and IV-B-47
in the docket.
Table 3.--Achievable Emission Levels For Combustion Control
------------------------------------------------------------------------
Achievable
Pollutant/combustion level emission
levels
------------------------------------------------------------------------
PM, gr/dscf:
1-sec................................................... 0.35
2-sec................................................... 0.25
Dioxin, ng/dscm:
1-sec................................................... 9,000
2-sec................................................... 800
TEQ dioxin, ng/discm:
1-sec................................................... 275
2-sec................................................... 15
CO, ppmdv:
1-sec................................................... 700
2-sec................................................... 40
HCl, ppmdv................................................ 3,100
SO2, ppmdv................................................ 55
NOx, ppmdv................................................ 250
Pb, mg/dscm............................................... 10
Cd, mg/dscm............................................... 4
Hg, mg/dscm............................................... 7.5
------------------------------------------------------------------------
Most of the achievable emission levels associated with combustion
control have changed little from the proposal; the exceptions are the
achievable emission levels for dioxin and Hg. The conclusion drawn at
proposal regarding the achievable emission level for dioxin was driven
by two relatively high data points from two different MWI. A thorough
review of these two MWI and the tests conducted at these two MWI raise
numerous questions and doubts about whether good combustion was
actually employed at these MWI during the emission tests. Consequently,
EPA no longer considers these emission tests representative of good
combustion.
The situation is similar with regard to achievable Hg emission
levels; at proposal, the conclusion regarding achievable emission level
for Hg was driven by one very high data point. Following proposal, the
hospital operating this MWI instituted several common waste management
practices employed by other hospitals, and the MWI was retested by the
EPA. The new data point is very similar to all the other data points.
Consequently, the earlier data point is no longer considered
representative of achievable Hg emission levels.
While no specific comments were received regarding the cost of good
combustion, the costs were reassessed and updated for consistent
comparison with other costs. This information is described in more
detail in item IV-B-33 in the docket.
2. Wet Scrubbers
Following proposal, a number of comments were submitted to the EPA
concerning the performance capabilities of wet scrubbing systems. Some
commenters claimed that the wet scrubbing system tested by EPA was not
representative of current wet scrubber technology and that the scrubber
was not designed for high efficiency PM removal. The commenters
submitted a number of emission test reports from wet scrubbing systems
and urged EPA to reconsider the performance capabilities of these
systems.
The EPA has reviewed these emission test reports and revised its
previous conclusions on the performance capabilities of wet scrubbing
systems. Wet scrubbing systems are capable of achieving three different
levels of performance, depending on their design and operation. For
convenience, these three levels of performance have been termed low
efficiency, moderate efficiency, and high efficiency. A summary of
EPA's revised conclusions regarding achievable emission levels
associated with the use of wet scrubbing systems is shown in Table 4. A
full discussion of these revised conclusions is available as item No.
IV-B-48 in the docket.
Table 4.--Achievable Emission Levels For Wet Scrubbers
----------------------------------------------------------------------------------------------------------------
Achievable emission levels
Pollutant, units ------------------------------------------------------------------------------
Low Moderate High
----------------------------------------------------------------------------------------------------------------
PM, gr/dscf...................... 0.05..................... 0.03.................... 0.015.
dioxin, ng/dscm.................. 125...................... 125..................... 125.
TEQ dioxin, ng/dscm.............. 2.3...................... 2.3..................... 2.3.
HCl, ppmdv....................... 15 or 99%................ 15 or 99%............... 15 or 99%.
Pb, mg/dscm...................... 1.2 or 70%............... 1.2 or 70%.............. 1.2 or 70%.
Cd, mg/dscm...................... 0.16 or 65%.............. 0.16 or 65%............. 0.16 or 65%.
Hg, mg/dscm...................... 0.55 or 85%.............. 0.55 or 85%............. 0.55 or 85%.
----------------------------------------------------------------------------------------------------------------
Percent reflects achievable percentage reduction in emissions. No levels are shown for CO, SO2, or NOx because
wet scrubbers on MWI achieved no further reductions beyond good combustion for these pollutants.
Note that for the waste-related pollutants, the achievable emission
levels in the table are expressed as a numerical concentration level or
a percent reduction. The composition of the waste burned in an MWI is
not uniform; as a result, the concentration levels of waste-related
pollutants from an MWI varies. On occasion, however, a momentary rise
or ``spike'' in the concentration level of a waste-related pollutant
may occur; while a wet scrubbing or dry scrubbing system can reduce
this concentration level considerably, the system can not necessarily
reduce it to the concentration levels shown in the table. For this
reason, conclusions regarding
[[Page 31743]]
achievable emission levels associated with the use of wet or dry
scrubbing systems for waste-related pollutants must include a percent
reduction component to accurately reflect the performance capabilities
of wet and dry scrubbing systems.
Also note that the EPA has no emission data upon which to assess
the performance capabilities of wet scrubbing systems that might
utilize activated carbon. The EPA knows of no wet scrubbing system
currently operating on an MWI using activated carbon, although vendors
have mentioned this technique could be done. Activated carbon used with
a dry scrubber (discussed below) provides enhanced removal of Hg and
dioxin. Thus, the use of activated carbon with a wet scrubbing system,
in an appropriate manner such as a fixed bed, should achieve the same
enhanced performance levels.
Along with new information regarding the performance of wet
scrubbers, EPA received new information regarding the cost of wet
scrubbing systems. Figure 1 shows the relationship between cost and
size of MWI for each level of wet scrubber performance. These costs are
not substantially different from those used at proposal. The key
difference is the distinction in costs between wet scrubbers of
different efficiency. This information is described in more detail in
item IV-B-30 in the docket.
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3. Dry Scrubbers
Very few comments were submitted to EPA following proposal that
questioned EPA's conclusions on the performance capabilities of dry
scrubbing systems. These capabilities were reassessed, however, to
consider data contained in several emission test reports submitted to
EPA from dry scrubbing systems using activated carbon.
The results of this reassessment of dry scrubbing system
performance is shown in Table 5. The conclusions summarized in this
table are similar to those at proposal. Note, however, that as
discussed above under wet scrubbing systems, the achievable emission
levels associated with the use of dry scrubbing systems for waste-
related pollutants are now expressed as a numerical concentration level
or a percent reduction. A discussion of this reassessment is available
as item No. IV-B-49 in the docket.
Table 5.--Achievable Emission Levels For Dry Scrubbers With Activated
Carbon Injection
------------------------------------------------------------------------
Pollutant, units Achievable emission levels
------------------------------------------------------------------------
PM, gr/dscf............................ 0.015.
dioxin, ng/dscm........................ 25.
TEQ dioxin, ng/dscm.................... 0.6.
HCl, ppmdv............................. 100 or 93%.
Pb, mg/dscm............................ 0.07 or 98%.
Cd, mg/dscm............................ 0.04 or 90%.
Hg, mg/dscm............................ 0.55 or 85%.
------------------------------------------------------------------------
Percent reflects achievable percentage reduction in emissions. No levels
are shown for CO, SO2, or NOx because dry scrubbers on MWI's achieved
no further reductions beyond good combustion for these pollutants.
While no specific comments were received regarding the cost of dry
scrubbers, the costs were reassessed and updated for consistent
comparison with other costs. Figure 2 shows the relationship between
cost and size of MWI for dry scrubbing systems. This information is
described in more detail in item IV-B-32 in the docket.
[[Page 31744]]
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D. MACT Floor
1. Existing MWI
The Clean Air Act specifies in Section 129 that the degree of
reduction in emissions that is deemed achievable for existing MWI shall
not be less stringent than the average emission limitation achieved by
the best performing 12 percent of units in a category; this requirement
is referred to as the ``MACT floor'' for existing MWI. Section 302(k)
of the Clean Air Act defines the term ``emission limitation'' as ``a
requirement established by the State or Administrator which limits the
quantity, rate, or concentration of emissions of air pollutants on a
continuous basis.''
Air quality permits and State regulations were examined to
determine the average emission limitations achieved by the best
performing 12 percent of MWI in each of the three subcategories
considered at proposal (continuous, intermittent, and batch MWI). Table
6 presents the MACT floor emission levels identified at proposal.
Table 6.--Proposed MACT Floor Emission Levels For Existing MWI
[February 1995]
----------------------------------------------------------------------------------------------------------------
MWI subcategory
Pollutant, units -----------------------------------------------
Batch Intermittent Continuous
----------------------------------------------------------------------------------------------------------------
PM, gr/dscf..................................................... 0.03 0.03 0.02
CO, ppmdv....................................................... 91 90 76
Dioxin, ng/dscm................................................. NF NF NF
HCI, ppmdv...................................................... 911 115 43
(35%) (92%) (97%)
SO2, ppmdv...................................................... NF NF NF
NOX, ppmdv...................................................... NF NF NF
Pb, mg/dscm..................................................... NF NF NF
Cd, mg/dscm..................................................... NF NF NF
Hg, mg/dscm..................................................... NF NF NF
----------------------------------------------------------------------------------------------------------------
NF=No Floor--the MACT floor emission levels for these pollutants reflect uncontrolled emissions. Numbers in
parentheses indicate percent reduction.
Note that the table indicates no floor for most pollutants. While a
numerical value was calculated for each pollutant, most pollutant MACT
floors reflected uncontrolled emissions. Nevertheless, based on
conclusions drawn at proposal regarding performance of technology, the
MACT floor values included in Table 6 for CO, PM, and HCl indicated, at
proposal, that all existing MWI would need good combustion and dry
scrubbers to meet the MACT floors for CO, PM, and HCl.
As discussed in earlier sections, the new information submitted
following proposal led to changes to the MWI inventory and
subcategories. Because these factors can influence the MACT floors, a
review of the MACT floors was conducted. Recall that the inventory
includes emission limitations for each pollutant based on State permits
and regulations. For each pollutant, the MWI inventory was sorted by
subcategory
[[Page 31745]]
and then by stringency of emission limit (most stringent to least
stringent) within each subcategory. For each pollutant, the emission
limitations for the top 12 percent of units in each subcategory were
averaged to determine the MACT floor emission levels. The results of
these calculations to determine the MACT floor emission levels for
existing MWI in each subcategory based on the new MWI inventory are
presented in Table 7.
Table 7.--Revised MACT Floor Emission Levels for Existing MWI
----------------------------------------------------------------------------------------------------------------
MWI subcategory
Pollutant, units -----------------------------------------------
Small Medium Large
----------------------------------------------------------------------------------------------------------------
PM, gr/dscf..................................................... 0.086 0.043 0.021
CO, ppmdv....................................................... 156 98 87
Dioxin, ng/dscm................................................. NF NF NF
HCI, ppmdv...................................................... NF 589 101
(57%) (93%)
SO2, ppmdv...................................................... NF NF NF
NOX, ppmdv...................................................... NF NF NF
Pb, mg/dscm..................................................... NF NF NF
Cd, mg/dscm..................................................... NF NF NF
Hg, mg/dscm..................................................... NF NF NF
----------------------------------------------------------------------------------------------------------------
NF=No Floor--the MACT floor emission levels for these pollutants reflect uncontrolled emissions. Numbers in
parentheses indicate percent reduction.
Based on the recalculated MACT floors and the new conclusions drawn
regarding the performance capabilities of air pollution control
technologies (Section II.C.), it appears that large MWI would have to
use good combustion and a high efficiency wet scrubber to achieve the
MACT floor emission levels, while a medium-sized MWI would have to
install at least good combustion and a moderate efficiency wet
scrubber. Dry scrubbers could also be used in conjunction with good
combustion to meet the MACT floor emission levels for medium and large
MWI. Available data showing the performance capabilities of good
combustion appears to indicate that the 0.086 gr/dscf PM MACT floor for
small MWI is not achievable with good combustion alone. However, MWI
manufacturers have indicated they routinely guarantee achieving 0.08
gr/dscf with good combustion. Consequently, the MACT floor for small
MWI would require the use of good combustion practices; based on the
claims of MWI manufacturers, add-on scrubbing systems would not be
needed in all cases to meet the MACT floor. Regulatory options
reflecting more stringent guidelines for existing MWI are examined in
Section III of this notice. A memorandum that documents the procedures
used to determine the MACT floors for existing MWI is located in the
docket as item IV-B-24.
2. New MWI
The Clean Air Act specifies in Section 129 that the degree of
reduction in emissions that is deemed achievable for new MWI shall not
be less stringent that the emissions control achieved by the best-
controlled similar unit; this requirement is referred to as the ``MACT
floor'' for new MWI. The MACT floor emission levels identified at
proposal for new MWI are presented in Table 8. These MACT floor values
reflect conclusions at proposal about the performance capabilities of
dry scrubbing systems because such systems were identified on at least
one MWI in each subcategory and because dry scrubbing systems were
considered capable of achieving lower emissions than wet scrubbing
systems.
Table 8.--Proposed MACT Floor Emission Levels For New MWI
[February 1995]
----------------------------------------------------------------------------------------------------------------
MWI subcategory
Pollutant, units -----------------------------------------------
Batch Intermittent Continuous
----------------------------------------------------------------------------------------------------------------
PM, gr/dscf..................................................... 0.013 0.013 0.013
CO, ppmdv....................................................... 50 50 50
Dioxin, ng/dscm................................................. 1,500 450 80
HCl, ppmdv...................................................... 42 42 42
(97%) (97%) (97%)
SO2, ppmdv...................................................... NF NF NF
NOX, ppmdv...................................................... NF NF NF
Pb, mg/dscm..................................................... 0.1 0.1 0.1
Cd, mg/dscm..................................................... 0.05 0.05 0.05
Hg, mg/dscm..................................................... NF NF 0.47
(85%)
----------------------------------------------------------------------------------------------------------------
NF=No Floor--the MACT floor emission levels for these pollutants reflect uncontrolled emissions. Numbers in
parentheses indicate percent reduction.
Again, the new information submitted following proposal led to
changes to the MWI inventory, subcategories, and conclusions about
performance of technology. Because these factors can influence the MACT
floors, a review of the MACT floors was conducted. The revised
inventory of existing MWI was examined to identify the best-controlled
[[Page 31746]]
MWI in each subcategory. The revised MACT floor emission levels for new
MWI are shown in Table 9.
Table 9.--Revised MACT Floor Emission Levels For New MWI
----------------------------------------------------------------------------------------------------------------
MWI subcategory
Pollutant, units -----------------------------------------------
Small Medium Large
----------------------------------------------------------------------------------------------------------------
PM, gr/dscf..................................................... 0.03 0.015 0.015
CO, ppmdv....................................................... 40 40 40
Dioxin, ng/dscm................................................. 125 125 25
HCl, ppmdv...................................................... 15 15 15
(99%) (99%) (99%)
SO2, ppmdv...................................................... NF NF NF
NOx, ppmdv...................................................... NF NF NF
Pb, mg/dscm..................................................... 1.2 0.07 0.07
(70%) (98%) (98%)
Cd, mg/dscm..................................................... 0.16 0.04 0.04
(65%) (90%) (90%)
Hg, mg/dscm..................................................... 0.55 0.55 0.55
(85%) (85%) (85%)
----------------------------------------------------------------------------------------------------------------
NF=No Floor--the MACT floor emission levels for these pollutants reflect uncontrolled emissions. Numbers in
parentheses indicate percent reduction.
The small MWI subcategory consists of MWI operating at a throughput
of 200 pounds per hour (lb/hr) or less of medical waste. The MACT floor
for new small MWI consists of the emission levels that are achievable
with good combustion and a moderate efficiency wet scrubber. The MACT
floor is based on these emissions levels because small existing MWI
equipped with this air pollution control have been identified. No small
existing MWI have been identified with high-efficiency wet scrubbers or
dry scrubbers.
The medium MWI category consists of MWI operating at a throughput
of greater than 200 lb/hr and less than or equal to 500 lb/hr of
medical waste. The MACT floor for new medium-sized MWI is based on
emission levels that are achievable with good combustion and a
combination of two control technologies, the high efficiency wet
scrubber and the dry injection/fabric filter (DI/FF) dry scrubber
system without carbon. At least one existing MWI in the medium
subcategory is controlled with a high efficiency wet scrubber and
another is equipped with a DI/FF system without carbon. The MACT floor
is based on both of these technologies (i.e., a combined dry/wet
scrubber system) because the wet scrubber achieves the lowest dioxin,
HCl, and Hg emissions, but the DI/FF without carbon injection achieves
the lowest Pb and Cd emissions. While no combined dry/wet scrubber
systems were identified on medium MWI, several such systems are
currently in operation on large MWI, as mentioned below. In addition,
as also mentioned below, spray dryer/fabric filter systems could also
meet the MACT floor emission levels for medium-sized MWI.
The large MWI subcategory consists of all MWI operating at a
throughput of greater than 500 lb/hr of medical waste. As with the MACT
floor for new medium MWI, the MACT floor for new large MWI is based on
the emission levels that are achievable with good combustion and a
combination of two control technologies, the high efficiency wet
scrubber and the DI/FF dry scrubber system with carbon. Several
existing facilities in the large category currently control emissions
with a combined dry/wet system. In addition, one existing MWI equipped
with a spray dryer/fabric filter system with carbon was tested during
the EPA testing program and this test demonstrated that this scrubbing
technology could also meet the MACT floor emission levels presented in
Table 9.
Regulatory options reflecting more stringent standards for new MWI
are examined in Section IV of this notice. A memorandum that documents
the procedures used to determine the MACT floors for new MWI is located
in the docket as item IV-B-38.
E. Baseline Emissions
To estimate the environmental impacts of the standards and
guidelines for MWI, an estimate of baseline emissions must be made
(i.e., emissions in the absence of Federal regulations). In the
February 1995 proposal, baseline emissions were estimated for PM, CO,
dioxin, HCl, SO2, NOx, Pb, Cd, and Hg. When this estimate was
developed, very little information was available regarding the actual
number of MWI and the level of air pollution control associated with
each. The emission estimate was derived from an estimated 3,700 MWI
assumed to be operating with little, if any, air pollution control.
As discussed in previous sections, new information has led to new
conclusions about the MWI inventory, performance of technology, and
control levels associated with each existing MWI. As a result, revised
estimates of baseline emissions from existing MWI have been calculated
and are presented in Table 10.
Table 10.--Annual Baseline Emissions For Existing MWI
------------------------------------------------------------------------
Baseline
Pollutant, units emissions
------------------------------------------------------------------------
PM, Mg/yr................................................. 940
CO, Mg/yr................................................. 460
Dioxin g/yr............................................... 7,200
Dioxin g TEQ/yr........................................... 150
HCl, Mg/yr................................................ 5,700
SO2, Mg/yr................................................ 250
NOx, Mg/yr................................................ 1,200
Pb, Mg/yr................................................. 11
Cd, Mg/yr................................................. 1.2
Hg, Mg/yr................................................. 15
------------------------------------------------------------------------
To convert Mg/yr to ton/yr, multiply by 1.1. To convert g/yr to lb/yr,
divided by 453.6.
The results of these emission estimates are significantly lower
than estimates developed at proposal. For example, the estimate of
baseline emissions of dioxin toxic equivalency (TEQ) was 5,100 grams
per year (g/yr) at proposal; the current estimate is 150 g/yr. At
proposal, the estimate of Hg emissions from existing MWI was 64.6 tons
per year (tons/yr); the current estimate is 16.0 tons/yr.
The primary reason for the lower baseline emission estimate is the
much greater level of emission control found
[[Page 31747]]
at existing MWI than was assumed at proposal. Comment is requested on
the methodology and assumptions used to estimate baseline emissions
from existing MWI. Where information on specific air pollution control
equipment was not available, EPA used State regulatory emission limits
to predict the type of air pollution control equipment installed on
each existing MWI. Information is requested which would more accurately
reflect the actual air pollution control equipment installed on each
existing MWI. In addition, emission factors for each type of air
pollution control equipment were developed based on compliance test
reports. Comment is requested on whether these emission factors reflect
actual air emissions from these control devices over the life of the
equipment.
At proposal, baseline emissions were also estimated for new MWI in
the fifth year after adoption of the NSPS. These estimates were based
on a projected number of new MWI and their associated emission controls
that would be installed in the five years following promulgation of the
standards. As with the estimation of baseline emissions for existing
MWI, the estimate of baseline emissions for new MWI has also changed
significantly. This change is due primarily to the lower projected
number of new MWI and the emission control level associated with each
MWI. The revised baseline emissions estimates for new MWI are presented
in Table 11.
Table 11.--Annual Baseline Emissions For New MWI
------------------------------------------------------------------------
Baseline
Pollutant, units emissions
------------------------------------------------------------------------
PM, Mg/yr................................................. 28
CO, Mg/yr................................................. 14
Dioxin g/yr............................................... 47
Dioxin g TEQ/yr........................................... 1.1
HCl, Mg/yr................................................ 64
SO2, Mg/yr................................................ 28
NOx, Mg/yr................................................ 130
Pb, Mg/yr................................................. 0.39
Cd, Mg/yr................................................. 0.051
Hg, Mg/yr................................................. 0.21
------------------------------------------------------------------------
To convert Mg/yr to ton/yr, multiply by 1.1.
To convert g/y to 1b/yr, divided by 453.6.
The memoranda documenting these revised estimates of baseline
emissions from new and existing MWI can be found in the docket as items
IV-B-51 and IV-A-6.
F. Operator Training and Qualification
The proposed standards and guidelines included operator training
and qualification requirements for each MWI operator. These operator
training and qualification requirements included completion of (1) 24
hours of classroom instruction, (2) 4 hours of hands-on training, (3)
an examination developed and administered by the course instructor, and
(4) a handbook or other documentation covering the subjects presented
during the course. The instructor of the operator training course was
not to be employed by the owner or operator of the facility. To obtain
qualification, an operator was to complete the training course and have
either a minimum level of experience or satisfy comparable or more
stringent criteria established by a national professional organization.
The proposed standards and guidelines also required the owner or
operator of the facility to develop and annually update a site-specific
operating manual. This manual would summarize regulations, operating
procedures, and reporting and recordkeeping requirements in accordance
with the proposed standards and guidelines. The proposal required that
each MWI be operated by a trained and qualified operator or by an
individual under the direct supervision of a trained and qualified
operator. The trained and qualified operator would have to be on duty
and at the facility at all times while the incinerator is in operation.
Many comments were received on the proposed operator training and
qualification requirements. The majority of the public comments on
operator training and qualification were related to the third party
training requirement and to the duration that operators must be present
while the MWI is burning waste. Many commenters stated that the EPA
should allow facilities the option of providing training by in-house
personnel because the facility's own personnel would be most familiar
with the operation and maintenance of the incinerator. The commenters
indicated that smaller facilities that do not have the personnel could
use the services of trainers and inspectors that are not affiliated
with the facility.
Many commenters stated that the amount of time that the operator
was required to be present was excessive. Under the proposal, the
operator would have to be on-duty and at the facility during the time
that the combustion air blowers are operating. Several commenters
suggested that this would require operators to be at the incinerator
even when waste was not being burned. Several commenters also suggested
that the trained and qualified operator should be easily accessible
(either at the facility or on-call) while the incinerator is operating.
The EPA is inclined to adopt the operator training and
qualification requirements briefly summarized below and discussed in
greater length in document number IV-B-26, which is available in the
Docket. Cost estimates for operator training and qualification are
documented in item IV-B-39.
The owner or operator of an MWI would be responsible for ensuring
that one or more operators at the facility are qualified. Operator
training may be obtained through a State-approved program or by
completing a training course with (1) 24 hours of classroom
instruction, (2) an examination designed and administered by the course
instructor, and (3) reference material distributed to the attendees
covering course topics.
Operators may obtain qualification by completing a training course
and having one of the following levels of experience: (1) at least 6-
months' experience as an MWI operator, (2) at least 6-months'
experience as the direct supervisor of a qualified MWI operator, or (3)
completion of at least two burn cycles under the observation of two
qualified operators. To maintain qualification, the operator would be
required to complete and pass an annual review or refresher course of
at least 4 hours.
A fully trained and qualified operator would have to be easily
accessible, either at the facility or on-call at all times while the
incinerator is in operation. The trained and qualified operator may
operate the MWI directly or be the direct supervisor of one or more
individuals that charge waste, remove ash, etc. As proposed, the
emission guidelines for existing MWI would require that, 1 year after
approval of the State plan, MWI must be operated by a trained and
qualified operator.
G. Testing, Monitoring, and Inspection
Section 129(c) of the Clean Air Act requires the EPA to develop
regulations that include monitoring and testing requirements. The
purpose of these requirements is to allow the EPA to determine whether
a source is operating in compliance with the regulations.
As mentioned earlier, at proposal relatively few emission test
reports were available to EPA to judge the performance of air pollution
control technologies. These test reports were the result of EPA
emission testing at several MWI. For a variety of reasons, EPA gathered
data during these emission tests using three, 4-hour test runs. The
results of the three test runs were then averaged at each MWI to
calculate a measured emission level. This calculated emission level
represented an
[[Page 31748]]
average emission value over the 12-hour period (i.e., three, 4-hour
runs).
As a result, EPA's assessments of the performance capabilities of
air pollution control technologies and conclusions regarding the
appropriate emission limits to include in the proposed regulations were
based on the measured performance of technology averaged over a 12-hour
period. Emission levels, however, tend to fluctuate somewhat as part of
normal operation. Consequently, during short periods of time, emission
levels may occasionally be greater or lower than the average emission
level over a 12 hour period.
In developing a regulation based on the performance of a particular
technology, the level of performance demanded by the regulation must be
consistent with the level of performance that technology can achieve.
The period of time over which emissions are measured and then averaged
to determine compliance with the regulation, therefore, must correspond
to the period of time over which emission levels were measured and
averaged in determining the emission limits included in the regulation.
If this is not the case, a regulation could include emission limits
that a technology can achieve if emissions are averaged over a
relatively long period of time, but not if emissions are averaged over
a much shorter period of time. For this reason, the proposed regulation
required emission testing to determine compliance by averaging the
results of three, 4-hour test runs, consistent with the procedures
followed in gathering the emission data used to establish the emission
limits included in the regulation.
Many comments were received regarding this proposed requirement to
determine compliance using three, 4-hour test runs. These commenters
noted that a 4-hour test run was much longer than the more conventional
test run of about 1-hour; additionally, many hospitals and healthcare
facilities would normally not have sufficient waste on hand to
accommodate three, 4-hour test runs. Finally, several commenters stated
that the proposed emission testing requirements would substantially
increase the costs associated with emission testing. Consequently,
these commenters urged EPA to revise the emission testing requirements
and adopt the more conventional approach of relying on test runs of
about an hour in length.
As mentioned earlier, more than two dozen test reports were
submitted to EPA following the proposal, and these test reports now
form the basis for revised conclusions regarding the performance
capabilities of technology and the emission limits these technologies
can achieve. The EPA test methods were used to perform the emission
testing summarized in these reports. These methods include procedures
that require the collection of a sufficient sample to accurately
measure emission levels. For most air pollutants, this sample generally
corresponds to a test run of about an hour. The revised conclusions
discussed earlier, therefore, regarding the performance capabilities of
emission control technologies and the emission limits these
technologies can achieve, are based (for the most part) on emission
test data generated by averaging the results of three test runs of
about an hour each (i.e., a 3-hour test).
For this reason, the EPA is inclined to state in the final
regulations adopted for MWI that EPA test methods be followed when
performing any emission testing required to determine compliance with
the regulations. This requirement will ensure that compliance testing
follows the same procedures used to generate the emission data upon
which the emission limits in the final regulation were based. In most
cases, three test runs of about an hour each would be necessary to
determine compliance with the final regulations.
An exception to this requirement is emission testing to measure
dioxin emissions. The procedures in the EPA test method to ensure
sufficient sample is gathered to accurately measure dioxin emissions
frequently leads to test runs longer than 1 hour. Whatever the length
of the emission test, however, the emission testing procedures included
in the EPA test method for measuring dioxin emissions were followed in
the emission test reports submitted to EPA following proposal. As
discussed earlier, these emission test reports serve as the basis for
the dioxin emission limits included in the final regulations and, as a
result, the length of testing necessary to determine compliance will
automatically be consistent with the length of testing used to
determine the emission limits included in the regulations.
The proposed regulations also would have required annual emission
testing to determine compliance. While some commenters supported
emission testing annually or even more frequently (such as every 6
months), a number of commenters believed that annual testing would be
unnecessary or that testing should be required no more than every 5
years. Commenters felt that the requirements for inspections,
monitoring, and operator training are sufficient and much less
expensive than annual emission testing.
Other commenters suggested that the annual emission testing
requirement be replaced with a requirement for annual equipment
inspection/maintenance to ensure that burner settings, air flow rates,
and other operation parameters are properly adjusted. While the
proposal includes a requirement for annual equipment inspection and
maintenance, this requirement would have applied only to existing MWI
until air pollution control equipment had been installed and the MWI
was in compliance with all the emission limits in the regulations. The
purpose of the proposed annual equipment inspection and maintenance
requirements was to ensure that the MWI was in good working order and
physically capable of operating as well as it could operate until
compliance with the emission limits was demonstrated. A MWI in poor
operating condition will likely have higher emissions than a MWI in
good operating condition.
While some commenters stated inspections are not necessary and
others suggested that EPA should let the States decide whether
inspections are necessary, most commenters were generally supportive of
annual inspection and maintenance requirements. Several commenters also
stated that biannual inspections would not be unreasonable. Many of the
commenters supportive of inspection requirements, however, suggested
that the requirement for a ``third party'' inspection be deleted. These
commenters stated in-house personnel are more familiar with the details
and operating intricacies of the equipment installed at their sites. In
addition, serious liability concerns could arise from injury or damage
caused by ``third party'' inspection or maintenance. At this point, EPA
is inclined to include inspection and maintenance requirements wherever
annual stack testing is not required (see document IV-B-26 in the
docket for a description of injection/maintenance requirements). The
inspection would not have to be conducted by a third party.
The proposal also included various monitoring requirements,
requiring the use of continuous emission monitoring systems (CEMS) for
some pollutants and the monitoring of operating parameters for other
pollutants. Some commenters supported the proposed requirements for CO,
opacity, and oxygen (O2) CEMS. Another commenter suggested that
the requirements should be extended to require CEMS for Hg, HCl, and
PM; the commenter suggested that such instruments are available. On the
other
[[Page 31749]]
hand, several other commenters objected to the CEMS requirements in the
proposed rule. These commenters stated that CEMS are not justified,
especially for small MWI, because they are too expensive. These
commenters believe that monitoring operating parameters is a sufficient
substitute for CEMS once compliance has been demonstrated by an initial
emission test.
The monitoring requirements in the proposal for monitoring
operating parameters were structured around the use of dry scrubber
systems. Those who commented on these specific requirements generally
agreed that monitoring of these operating parameters was appropriate
for dry scrubbing systems.
No monitoring requirements were included for monitoring operating
parameters for wet scrubbing systems. The EPA solicited information
regarding an appropriate set of operating parameters for wet scrubbing
systems. The EPA was inclined and is still inclined to include specific
operating parameter monitoring requirements in the final regulations
for wet scrubbing systems as well as for dry scrubbing systems. To
accommodate MWI using an air pollution control system other than a dry
or wet scrubbing system, EPA is inclined to include provisions in the
final regulations for petitioning the Administrator to monitor specific
operating parameters associated with the other air pollution control
system.
A number of commenters responded to EPA's request for suggestions
of monitoring requirements for operating parameters suitable for wet
scrubbing systems. Suggested parameters included pressure drop across
the system, liquor flow rate, flue gas temperature, liquor pH, and
horsepower or amperage. While EPA is inclined to include the same
requirements in the final regulations for monitoring operating
parameters for dry scrubbing systems as proposed, EPA is inclined to
include requirements in the final regulations for monitoring the
following operating parameters for wet scrubbing systems: scrubber exit
temperature, scrubber liquor pH, scrubber liquor flow rate, and energy
input to the scrubber (e.g., pressure drop or horsepower).
To consider the comments outlined above regarding the frequency of
emission testing and the proposed inspection and monitoring
requirements, a matrix of options was developed. This matrix of options
and their annual costs are summarized in Table 12. Each cell or box in
this table represents a combination of emission testing and monitoring
requirements (some combinations also include inspection requirements).
The range in the costs shown in each cell is a reflection of how the
cost of emission testing and monitoring is likely to vary depending on
the emission limits included in the final regulation (i.e., whether the
emission limits are based on the use of good combustion alone or good
combustion and wet or dry scrubbing). These costs vary somewhat because
the operating parameters monitored in each case would be somewhat
different.
Table 12.--Monitoring/Testing Options and Annual Costs
[Thousand $/yr]
----------------------------------------------------------------------------------------------------------------
Testing options
-----------------------------------------------
Monitoring options A Initial and B Initial C Substitute
repeat stack stack testing; stack testing;
testing inspection inspection
----------------------------------------------------------------------------------------------------------------
1--CO CEMS (App F); Opacity CEM (no App F); Operating Parameters 110-119 100-104 99-102
2--Opacity and CO CEMS (no App F); Operating Parameters......... 96-104 85-89 83-86
3--Opacity CEMS (no App. F); Operating Parameters............... 37-46 27-31 26-29
4--Operating Parameters; Quarterly Method 9..................... 10-15 7.5-11 5.8-8.8
----------------------------------------------------------------------------------------------------------------
Table 12 presents the 12 possible combinations of three emission
testing options and four monitoring options that the EPA is considering
including in the final regulations. A more detailed explanation of
these emission testing and monitoring options, as well as their costs,
is available in the docket as item IV-B-54. The following discussion,
however, briefly outlines the essential requirements of each of the
monitoring and emission testing options.
Monitoring Option 1 requires a CO CEMS with Appendix F requirements
(Appendix F requirements ensure the data generated is reliable), an
opacity CEMS without Appendix F requirements, and operating parameter
monitoring requirements for the MWI and, if applicable, for the air
pollution control device. Because the use of Appendix F is required
under this option, the CO CEMS would be used for direct enforcement of
the CO emission limit. The opacity CEMS without Appendix F requirements
would simply provide an indication of opacity and would not be used for
direct enforcement of the opacity limit. Routine opacity testing with
Reference Method 9 is included in Monitoring Option 1 to compensate for
not including Appendix F requirements on the opacity CEMS.
Monitoring Option 2 is the same as Monitoring Option 1, except that
it would not include Appendix F requirements for the CO CEMS, which
would reduce costs. Without Appendix F requirements, the CO CEMS would
provide an indication of CO emissions and would not be used for direct
enforcement of the CO emission limit. Emission testing for CO is
included in Monitoring Option 2 to compensate for excluding Appendix F
requirements on the CO CEMS. An opacity CEMS and operating parameter
monitoring would be required as in Monitoring Option 1.
Monitoring Option 3 is the same as Monitoring Option 2, except
that, instead of the more expensive CO CEMS, stack emission testing for
CO would be required. An opacity CEMS and operating parameter
monitoring would be required as in Monitoring Options 1 and 2.
Monitoring Option 4 would require no CEMS. Instead, it would rely
on manual emission test methods (including more frequent Method 9
opacity tests) and operating parameter monitoring.
For each of these monitoring options, three emission testing
options have been developed. Emission testing Option A would require
initial and annual/skip tests. With the annual/skip test requirement,
emission tests would be required for the first 3 years. If these tests
show that the facility was in compliance each of these 3 years, then
subsequent testing would be done every third year. Emission testing
Option A,
[[Page 31750]]
under all four monitoring options, would require an initial stack test
for all pollutants. Annual or skip emission testing under Monitoring
Options 1, 2, and 3 would also require emission testing of all
pollutants. However, annual or skip emission testing under Monitoring
Option 4 would only require emission testing of a few key or critical
pollutants (i.e., only those necessary to gain a good indication that
the air pollution control system is operating properly).
Emission testing Option B would require an initial emission test
for all pollutants, but would not require annual emission tests. In
lieu of annual or skip emission testing, MWI inspection/maintenance
would be required. This inspection/maintenance would be required
annually under Monitoring Options 1 and 2; however, it would be
required quarterly under Monitoring Options 3 and 4, where no CO CEMS
is required. The inspection/maintenance could be done by in-house
personnel. With regard to any necessary repairs arising from the
inspection/maintenance, the owner or operator of the MWI would be
required to contact the State (or local, if delegated by the State) air
pollution control agency and negotiate a date, within 10 operating days
following the date of the inspection/maintenance, by which the repairs
must be completed.
Emission testing Option C would permit substitute emission testing.
A substitute emission test is an emission test conducted on another,
but identical MWI. An MWI would be required to petition the State (or
local, if delegated by the State) air pollution control agency for
approval, however, and the ``burden of proof'' would be on the MWI to
demonstrate to the satisfaction of the agency that the substitute
emission test is on an identical MWI. In addition, an initial emission
test for Hg would be required; this test would ensure that appropriate
measures for managing the mercury content of the waste are utilized
(e.g., material separation, material purchasing, etc.). Inspection/
maintenance requirements would be the same as under Emission Testing
Option B.
The most direct means of ensuring compliance with emission limits
included in regulations is the use of CEMS. As a matter of policy, the
first and foremost option considered by EPA is to require the use of
CEMS in regulations to demonstrate and ensure compliance on a
continuous basis with the regulations. Only when the impacts of
including such requirements are considered unreasonable, does the EPA
consider other options.
For MWI, it appears that almost all of the emission testing and
monitoring options under consideration cost more than the emission
control system that would be installed to meet the emission limits in
the regulations; in some cases, the emission testing and monitoring
requirements could cost twice as much as the emission control system.
Consequently, the Agency is inclined to include the emission testing
and monitoring requirements under Monitoring Option 4 in the final
regulations to minimize costs. Where the regulations are based on good
combustion and wet and/or dry scrubbing systems, the EPA is inclined to
require Monitoring Option 4 with Emission Testing Option A; where the
regulations are based, in part, on the use of good combustion alone,
the EPA is inclined to require Monitoring Option 4 with Emission
Testing Option B.
The appropriate choice of emission testing and monitoring
requirements (as well as inspection/maintenance requirements) is an
area in which the EPA specifically solicits comments. Many of the MWI
visited or inspected by the EPA in the course of gathering data and
information often appeared poorly maintained and operated. Inadequate
maintenance and/or operation can cause even the best equipment to
perform poorly and result in excess emissions. The inspection/
maintenance and operator training requirements included in the final
regulations are expected to address this problem in a satisfactory
manner; however, the EPA is interested in whether others feel the
inspection/maintenance requirements and operator training requirements
should be supplemented with more extensive emission testing and/or
monitoring requirements.
In addition, CEMS vendors have expressed concern with the costs
developed by EPA for the various CEMS and operating parameter
monitoring requirements. In particular, they believe the costs of CEMS
are much lower than those estimated by EPA. As mentioned, a detailed
breakdown of the EPA estimates of the costs of these requirements is
available in the docket as item IV-B-54. The EPA solicits comments on
these costs and if costs are indeed much lower than estimated, EPA may
consider more comprehensive monitoring requirements in the final rule.
Finally, even if the costs remain similar to those previously
estimated, the EPA is considering more comprehensive emission testing
and monitoring requirements (including CEMS) for large MWI that burn
medical waste generated offsite (i.e., generated at another location
than that of the MWI).
Definition of Medical Waste
Section 129 of the Clean Air Act directs the EPA to adopt
regulations for solid waste incineration units that combust (1)
municipal waste; (2) hospital, medical, and infectious waste; (3)
commercial or industrial waste; and (4) all other solid waste. The
regulations limiting air emissions from solid waste incineration units
combusting municipal waste (otherwise known as municipal waste
combustor(s) or MWC) were promulgated on December 19, 1995 (60 FR
65387). In developing regulations to limit air emissions from solid
waste incineration units combusting hospital, medical, and infectious
waste (otherwise known as medical waste incinerator(s) or MWI), medical
waste was defined as any solid waste that is generated in the
diagnosis, treatment, or immunization of human beings or animals, in
research pertaining thereto, or in the production or testing of
biologicals.
Section 129(g)(6) states that the term ``medical waste'' shall have
the meaning ``established by the Administrator pursuant to the Solid
Waste Disposal Act'' (SWDA). For the proposed air emission standards
and guidelines for MWI, EPA adopted the definition of ``medical waste''
from solid waste regulations codified in 40 CFR part 259, subpart B
because this definition was ``established by the Administrator pursuant
to the [SWDA],'' as amended by the Medical Waste Tracking Act (MWTA).
However, 40 CFR part 259 has since been withdrawn. Consequently, there
is no definition of medical waste which has been ``established by the
Administrator pursuant to the [SWDA],'' and EPA now has the flexibility
to examine and consider other definitions of medical waste. While EPA
is inclined to adopt a specific definition described below, EPA is
considering all of the definitions discussed in this section as well as
the proposed definition and solicits comment on the merits of each
definition discussed as well as other definitions EPA should consider.
During the public comment period, the majority of the comments on
the definition of medical waste stated that the proposed definition was
too broad and that it should be narrowed. Several commenters stated
that this definition would aggravate an already confusing situation,
where the public distinction between the terms medical waste and
infectious waste has become blurred and in most cases lost; these terms
are often used synonymously in public discourse.
[[Page 31751]]
These commenters believed that a broad definition of medical waste
in the regulations for MWI would have the undesirable impact of
fostering and encouraging the use and adoption of this definition in
other areas and by other regulatory authorities. They suggested that as
this definition becomes more widespread and adopted by others,
healthcare facilities would eventually be forced to handle most, if not
all, medical waste as infectious waste--whether it was burned in an
incinerator or not.
These commenters stated the proposed definition of medical waste,
because of the loss of public distinction between this term and the
term infectious waste, and the resulting impact of eventually forcing
healthcare facilities to treat most waste as infectious waste, would
lead to a massive increase in the volume of infectious waste. This
increase would, in turn, lead to a major increase in the costs of
disposal of waste from hospitals, since most waste would have to be
handled as infectious waste.
These commenters stated that, as in implementing the MWTA,
healthcare facilities should be viewed as generating two waste streams:
a medical waste stream, which is usually defined by the potential for
disease transmission and requires special handling; and a noninfectious
waste or ``healthcare trash'' waste stream, which has no potential for
infection and is treated and handled as municipal waste. These
commenters urged EPA to narrow the definition of medical waste used in
the MWI regulations to one of infectious waste, analogous to the term
``regulated medical waste'' adopted in regulations resulting from the
MWTA.
In most--if not all--cases, these commenters indicated that, where
healthcare facilities operate medical waste incinerators, they burn
infectious medical waste or a mixture of infectious medical waste and
noninfectious waste (i.e., healthcare trash). These commenters stated
that there were very few, if any, medical waste incinerators operated
by healthcare facilities that burned only noninfectious waste or
healthcare trash.
Consequently, by defining medical waste narrowly, in a manner
consistent with infectious or regulated medical waste, and by applying
the regulations to incinerators that burn this waste or any mixture of
this waste and other waste, the EPA could achieve the objective, which
is regulating air pollution from medical waste incinerators at
healthcare facilities; this objective would be achieved without adding
to the confusion or leading to the serious impacts outlined above.
These commenters further stated the proposed definition of medical
waste would subject MWC, which burn general nonregulated and
noninfectious waste from hospitals, to the same requirements as those
proposed for MWI. Consequently, even if healthcare facilities were not
eventually forced to handle most waste as infectious waste (because MWC
that burn general nonregulated and noninfectious waste from hospitals
would be subject to the MWI regulations) this broad definition would
result in higher disposal costs for healthcare facilities which send
their general nonregulated and noninfectious waste to MWC for disposal.
Some commenters, on the other hand, support the proposed broad
definition of medical waste. These commenters pointed out that there is
little difference in the air emissions created by burning infectious
medical waste (e.g., regulated medical waste or ``red bag'' waste) and
by burning noninfectious waste (e.g., nonregulated medical waste or
healthcare trash). As a result, the regulations should apply to the
burning of all medical waste, as EPA proposed. These commenters believe
that EPA's use of the broad definition of medical waste, solely for the
purpose of defining what type of incinerator the regulations apply to,
does not imply that more waste or that all medical waste will be
considered infectious waste. Merely requiring that incinerators that
burn medical waste must limit air pollution will not require all
healthcare facilities to handle all their medical waste as infectious
waste.
In fact, these commenters indicated that many healthcare facilities
today routinely separate their waste into two types: infectious waste
(``red bag'') and noninfectious waste (``black bag''). Numerous items
of waste from healthcare facilities are not, nor need not be considered
infectious waste. On the other hand, many healthcare facilities today
do little to separate their waste streams; most waste is handled and
treated as infectious waste. If waste disposal costs were of paramount
concern to healthcare facilities, those that do little separation today
could reduce their present waste disposal costs by more carefully
segregating their waste into infectious and noninfectious waste streams
and properly disposing of these two waste streams.
Finally, several commenters questioned whether animal carcasses and
pathological waste should be included in the definition of medical
waste. These commenters were uncertain as to whether pathological waste
incinerators were to be regulated as MWI or separately. These
commenters requested clarification of this situation and urged EPA to
regulate pathological wastes separately from medical waste.
Similarly, several commenters questioned whether ``out-of-date'' or
``off-spec'' drugs, or radio-active type medical wastes, should be
included in the definition of medical waste. These commenters requested
special treatment for these types of wastes, similar to that proposed
for pathological wastes.
The EPA did not intend to add or contribute to the confusion that
presently exists in the public discourse regarding the distinction or
lack of distinction between the terms medical waste, regulated medical
waste, and infectious medical waste. In fact, the EPA would like to
state very clearly that numerous items within the medical waste stream
are noninfectious and need not be treated as infectious. In fact, the
majority of items in the medical waste stream are noninfectious, and in
terms of percentages, most authorities conclude that only 10 to 15
percent of the items in the medical waste stream are infectious, or
potentially infectious, and warrant special treatment or handling.
In considering the public comments, an interesting and unanimous
agreement emerges, even if it is not stated as such. All of the
commenters seem to agree that healthcare facilities can be viewed as
generating two waste streams: an infectious medical waste stream and a
noninfectious healthcare trash, or ``municipal waste'' type, waste
stream. The challenge for EPA, therefore, is to reconcile the agreement
in this area with the requirement of the Clean Air Act to develop
regulations for incinerators burning hospital, medical, and infectious
waste.
The Clean Air Act requires EPA to develop regulations for the
burning of medical waste; but it also requires EPA to develop
regulations for the burning of municipal waste. In fact, EPA adopted
regulations limiting air pollution from the burning of municipal waste
on December 19, 1995 (60 FR 65387). As a result, if healthcare
facilities are viewed as generating two types of waste streams, an
infectious waste stream and a municipal waste stream, then the burning
of the municipal waste stream is already covered by regulations.
The definition of municipal waste included in the regulations
covering the burning of municipal waste states:
Municipal solid waste * * * means household, commercial/retail,
and/or institutional waste * * * Commercial/retail waste includes
material discarded by stores,
[[Page 31752]]
offices, restaurants * * * Institutional waste includes materials
discarded by schools, nonmedical waste discarded by hospitals, * * *
and material discarded by other similar establishments or
facilities.
The regulations cover the burning of municipal waste discarded from
offices and institutions. Hospitals are cited as an example of an
institution and clinics and nursing homes are considered ``similar
establishment(s)''. Offices include doctors' offices, dentists'
offices, etc. Consequently, noninfectious, municipal-type waste
discarded from healthcare facilities is considered part of the
municipal waste stream and is covered by the regulations adopted for
the burning of municipal waste.
The remaining need, therefore, is to regulate the burning of the
infectious waste stream discarded from healthcare facilities, which can
be achieved by redefining medical waste in terms of infectious or
potentially infectious materials. Thus, the EPA is inclined to narrow
the applicability of the proposed regulations by adopting a definition
of medical waste that focuses on that portion of the overall medical
waste stream that is generally considered infectious or potentially
infectious.
Given the confusion and number of varying definitions of medical
waste, regulated medical waste, infectious waste, etc., at the Federal
and State level, and within the healthcare community, transportation
sector, etc., EPA does not intend to add to this confusion by creating
another definition. As a result, EPA is inclined to adopt a definition
of medical waste, for the MWI regulations, from among those already in
use.
As mentioned, numerous definitions are currently in use, such as
the definition of infectious waste created by the U.S. Department of
Transportation, the definition of regulated medical waste created by
EPA, as well as other definitions created by other regulatory agencies
and national associations, such as the Occupational Safety and Health
Administration, the New York State Department of Health, the American
Hospital Association, etc. While these are just a few of the agencies
or associations that have developed definitions of medical waste that
are currently in use, they are the ones most often cited or suggested
in the public comments. Each of these definitions are slightly
different, but all focus on infectious or potentially infectious
medical waste. These definitions are discussed in more detail in
document number IV-B-25, available in the Docket.
For the most part, infectious or potentially infectious wastes are
defined through the use of categories or classes of wastes. The classes
of wastes most commonly used include:
1. Cultures and stocks of infectious agents;
2. Human pathological wastes;
3. Human blood and blood products;
4. Used sharps;
5. Animal wastes;
6. Isolation wastes; and
7. Unused sharps.
These seven waste classes are commonly used by various agencies and
associations as the basis for defining medical wastes. However, while
the classes of wastes included in two different definitions may be
identical, the specific items included under each class and the
definitions for these items may be very different. Each agency or
association has developed different language to define each of these
waste classes in a way that best serves their purposes. For example,
some definitions include intravenous (IV) bags under class 3 wastes,
while others do not.
It appears that adoption of any one of these definitions or any
definition at all will be controversial. No uniform or widespread
agreement on a definition exists, and for each commenter who argued
strongly for adoption of one particular definition, another commenter
argued equally strongly for adoption of a different one.
Of all these definitions, EPA is inclined to adopt the New York
State Department of Health (NYSDOH) definition, which is one of the
more recently developed definitions for use in the MWI air pollution
emission regulations. This definition was subjected to intense
discussion, consideration, and review within the medical and healthcare
community. Because it was adopted fairly recently, this definition also
benefits from the various controversies and discussions generated by
adoption of earlier definitions by other agencies and associations.
Further, this definition seems to be among the more comprehensive ones
in terms of identifying and defining the various classes of infectious
or potentially infectious medical waste mentioned above.
The NYSDOH definition includes six of the seven waste classes;
isolation wastes (class 6) are not listed as a separate category. The
definitions used for waste classes 1, 2, 4, and 7 are similar to those
used by the MWTA definition. As with the AHA definition, the NYSDOH
definition differs from the MWTA definition in the specifics of class 3
wastes. Class 3 waste under the NYSDOH definition does not include
items caked with dried blood or IV bags. These wastes are included in
the MWTA definition of class 3 waste. The definitions for class 5 waste
only includes wastes from animals exposed to infectious agents during
research, the production of biologicals, or the testing of
pharmaceuticals. Pathological waste from veterinary facilities is
excluded from the MWTA definition. The NYSDOH defines class 5 wastes as
wastes from animals known to be contaminated with infectious agents or
from animals inoculated during research, the production of biologicals,
or pharmaceutical testing. Unlike the MWTA definition, the NYSDOH
definition seems to include some wastes (from animals contaminated with
infectious agents) generated by general veterinary practices. The
specifics of this definition are included in item IV-J-078 in the
docket).
Also, as stated at proposal, the EPA is inclined to exclude
crematories and incinerators used solely for burning pathological waste
(human or animal remains and tissues) from the medical waste
incinerator regulation. However, MWI that burn animal and pathological
waste co-mingled with other classes of medical waste would be subject
to the regulation. Because MWI that burn mixtures of medical and
pathological (or animal) waste would be covered by the regulation, it
is necessary to include a description of pathological and animal waste
in the definition of medical waste. Human pathological waste and animal
waste are included in the NYSDOH definition of medical waste.
In addition, the EPA is inclined to exclude from the regulation
incinerators used solely for burning ``off-spec'' or ``out of date''
drugs or pharmaceuticals, as well as incinerators used solely for
burning radio-active type medical wastes. In other words, as several
comments suggested, the EPA is inclined to treat these wastes in a
manner similar to pathological waste.
While EPA is inclined to exclude these types of wastes from the
regulation for MWI, this exclusion does not mean that EPA will not
develop regulations which will cover these wastes. The Clean Air Act
clearly directs the EPA to develop regulations to cover burning of
these wastes. Thus, this inclination to exclude them is only to
temporarily defer regulation.
The Clean Air Act directs the EPA to develop regulations for all
solid waste incinerators, and burning these wastes will be covered by
regulations developed within the next few years. The Clean Air Act also
directs the EPA to announce a schedule for development
[[Page 31753]]
of these other regulations, and the EPA has announced these regulations
will be developed by the year 2000.
I. Pyrolysis Units
Incineration is only one of several medical waste treatment
technologies. Other treatment technologies, such as autoclaves,
microwaves, and chemical treatment, where there is clearly no
combustion occurring, are referred to in this notice as ``alternative
technologies'' and are discussed further in Section II.J. These
``alternative technologies'' clearly are not subject to MWI
regulations. On the other hand, some medical waste treatment
technologies employ plasma or gasification processes (i.e., pyrolysis).
Because it appears that at least some combustion is taking place in
these devices, EPA considered these pyrolysis technologies covered by
the proposed MWI regulations.
Comments from the vendors of pyrolysis technologies indicated they
believed they could easily meet the emission limitations included in
the proposed MWI standards and guidelines. However, they believed that
their processes are unique enough to warrant a separate category for
regulation. The vendors were particularly concerned that the proposed
compliance and monitoring requirements for MWI do not apply to
pyrolysis technologies. The proposal, therefore, requested comment on
whether pyrolysis units should be regulated as MWI or as a separate
source category.
Numerous comments and suggestions were received following proposal
from vendors of pyrolysis treatment technologies. Based on these
comments and suggestions, a draft regulation for pyrolysis treatment
technologies has been developed and is available in the docket as item
IV-B-56. This draft regulatory text is incomplete at this time. It
includes placeholders and requests for information where such
information is lacking. Comments are requested to help EPA fill in this
missing information.
A separate regulation for pyrolysis treatment technologies would
look very similar to the MWI regulation in that it would contain
definitions, emissions limitations, monitoring and testing requirements
to demonstrate compliance, and reporting and recordkeeping
requirements. It would differ from the MWI regulations in that some
definitions would be different, the emission limitations would, in many
cases, be more stringent than the MWI regulations, and the monitoring
and testing requirements would reflect the operating parameters that
are unique to pyrolysis systems.
The EPA is inclined to adopt separate regulations for pyrolysis
treatment technologies. The EPA specifically requests comment on the
merits of continued development of separate regulations for pyrolysis
systems. These systems appear to be very different than incinerators.
Because they are emerging technologies, however, the normal process of
determining a MACT floor and MACT for these systems is not possible at
this time. In fact, because they appear to be inherently clean
technologies, regulation of these systems may not be warranted at this
time.
J. Alternative Medical Waste Treatment Technologies
In the proposal, it was estimated that many owners of existing
onsite MWI would discontinue use of their existing MWI in favor of less
expensive medical waste disposal options to avoid the high cost of add-
on air pollution control equipment. In addition, many facilities that
would have chosen to purchase a new onsite MWI were estimated to be
likely to choose some other method of waste disposal. This phenomenon
was labeled as ``switching'' in the proposal, and it has already
occurred in a few States that have adopted stringent MWI regulations in
the past few years.
Next to onsite incineration, the two most common methods of medical
waste disposal are (1) offsite contract disposal, which usually
involves larger, commercial incinerators dedicated to medical waste and
(2) onsite alternative medical waste treatment technologies, which
include steam autoclaving, chemical treatment, and microwave
irradiation. Because the MWI regulation may encourage switching and the
use of onsite alternatives, the possible impacts of other waste
disposal methods were assessed. Although autoclaves, chemical treatment
systems, and microwave systems are not covered by the MWI standards and
guidelines, commercial medical waste incinerators would be subject to
the MWI standards and guidelines.
Following proposal, new data on commercial disposal facilities
throughout the U.S. were obtained. Information on the costs of
commercial disposal for medical waste generators in both urban and
rural locations was obtained. Also, information on the environmental
impacts of increased transportation of medical waste was developed.
This new information pertaining to commercial disposal was factored
into the economic and environmental impacts analyses presented in
Sections III and IV of this notice. The remainder of this section will
focus on information relating to nonincineration alternative
technologies (i.e., autoclaves, chemical treatment, microwave
irradiation, etc.).
During the public comment period following proposal, several
concerns were raised regarding the availability, effectiveness, costs,
and environmental impacts of onsite alternative treatment technologies.
Concerns were also raised regarding alternative technology operator
safety and State acceptance of alternative technologies. Because of the
concerns raised during the public comment period, the Agency has
examined the available information on the effects that switching from
onsite incineration to alternative technologies could have on medical
waste generators and the environment.
Following proposal, a great deal of information on alternative
technologies was received. This information was compiled and is
presented in document No. IV-B-43. The material presented in document
IV-B-43 should not be considered an in-depth study of alternative
technologies. Instead, it is a review of the available information.
Based on this information, there appears to be no significant or
substantial adverse economic, environmental, or health and safety
issues associated with the increased use of these nonincineration
alternative medical waste treatment technologies.
The most widely used nonincineration alternative technologies are
autoclaves, chemical treatment systems, and microwave systems. In
autoclaves, the effects of heat from saturated steam and increased
pressure are used to decontaminate the medical waste. In chemical
treatment systems, an antimicrobial chemical, such as sodium
hypochlorite, chlorine dioxide, or peracetic acid, is used to
decontaminate the waste. In microwave technologies, medical waste is
wetted and heated to decontaminating temperatures with microwave
irradiation.
Most alternative technologies are equipped with a shredder or
grinder that is used to reduce the volume of the waste by up to 80
percent and render the waste unrecognizable. In some alternative
technologies, the waste is compacted, and the waste volume is reduced
by 50 percent. With most alternative technologies, the mass of the
waste is not reduced due to the entrainment of liquids that are added
during treatment.
Because shredding or grinding pathological and animal waste may
present aesthetically unacceptable
[[Page 31754]]
results, most alternative technologies are not suitable treatment
methods for these types of waste. Also, alternative technologies are
usually unable to effectively treat chemotherapy, hazardous, or low-
level radioactive wastes. The total waste stream at a typical hospital
contains less than 3 percent by weight of pathological, animal,
chemotherapy, hazardous, and low level radioactive wastes. Facilities
using alternative technologies usually package this portion of the
waste and send it to a commercial disposal facility.
The efficacy of autoclave, microwave, and other thermal treatment
technologies depends primarily on the treatment time and temperature.
The efficacy of chemical treatment systems depends on the treatment
time and the chemical concentration. The most widely used criteria for
determining the efficacy of an alternative technology in
decontaminating the waste was developed by the State and Territorial
Association of Alternate Treatment Technologies (STAATT). The STAATT
criteria recommends, as a safe and satisfactory level of medical waste
treatment, the inactivation of vegetative bacteria, fungi, lipophilic/
hydrophilic viruses, and mycobacteria at a 6 Log10 reduction or
greater and the inactivation of Bacillus subtilis or Bacillus
stearothermophilus at a 4 Log10 or greater. Efficacy test reports
indicate that autoclave systems, chemical treatment systems, and
microwave systems can meet and exceed the STAATT efficacy criteria.
Therefore, the most widely used alternative treatment technologies seem
to be effective methods of decontaminating medical waste.
In most States, alternative technologies must undergo an approval
or permitting process before they can be installed in the State. As
long as the technology can demonstrate that it meets the State's
efficacy requirements, which are usually similar to, if not the same
as, the STAATT criteria, the technology can be installed, unless the
State determines that the technology is unacceptable for some other
reason. The State approval or permitting process usually takes less
than a year. Many alternative technology vendors have gained approval
of their systems in a number of States so that less time will be
required for review of the technology by State regulatory agencies
before the system is installed.
There are some 20 vendors of alternative technologies (i.e.
autoclaves, chemical treatment systems, and microwave systems) that
have a considerable number of installations. These vendors, when
combined, have about 150 years of experience in the medical waste
business. Some of these vendors have more than 15 years of experience
alone. These vendors are responsible for approximately 975 alternative
technology installations, which range in capacity from 12 to 8,000
pounds of medical waste treated per hour. An additional 17 alternative
technology vendors were identified with systems that are under
development and are expected to appear on the market in the near
future.
Alternative technologies seem to be available, and many vendors
have been in the medical waste business for many years. With the number
of vendors that have alternative technologies under development, the
alternatives industry appears to be growing. Alternative technology
vendors claim they will be able to meet any increased demand for onsite
alternative systems due to switching.
The results from reports on the air emissions from autoclaves show
that there are some emissions of volatile organics from autoclaves.
However, the test reports also show that the emissions of Pb, Cd, Hg,
HCl, and PM from autoclaves are insignificant when compared to
emissions of the same pollutants from MWI. No information on dioxin
emissions from autoclaves was available. The available data on the air
emissions from autoclaves shows that these emissions are more organic
than the acid gas and metal emissions from MWI. Furthermore, it appears
that on a pound of pollutant per pound of waste basis, far less total
emissions are produced from treating medical waste in an autoclave than
from burning waste in an MWI.
No data is available on the air emissions from chemical treatment
systems and microwave systems. However, some States require chemical
treatment systems to obtain air permits. The emissions from microwave
systems are likely to be similar to those from an autoclave since lower
temperatures are used during microwaving and the only component added
is water.
Based on the information received, there does not appear to be any
water pollution from the liquid effluents of autoclaves and chemical
treatment systems and no liquid effluent from microwave treatment
systems. The results of Toxicity Characteristics Leachate Procedure
(TCLP) tests conducted on waste treated in an autoclave and a chemical
treatment system were far below the regulatory threshold for metals and
organics. Since the only component added to waste that is treated in a
microwave system is water, the TCLP tests conducted on microwaved waste
should produce similar results to those of autoclaved waste.
The annualized price per pound of medical waste treatment with an
alternative technology is comparable to the price per pound associated
with other methods of medical waste treatment and disposal. For
facilities that wish to treat their medical waste onsite with an
alternative technology, but do not have the capital to purchase an
alternative system, options for leasing or renting an alternative
technology are available. According to alternative technology vendors,
leasing onsite medical waste treatment technologies is a common
practice. Most lease agreements are available either through the
alternative vendor directly or through a third party leasing company.
The results from a survey of hospitals that are currently using
autoclaves, chemical treatment systems, and microwave systems indicate
that these hospitals are pleased with the operation of their
alternative medical waste treatment systems. The hospitals indicated
that problems with shredder jams are rare and that odors are minimal
with the alternative systems. The surveyed hospitals reported that the
alternative technologies are cost effective and easy to operate. The
hospitals also indicated that the waste treated in their alternative
systems is readily accepted at local landfills. Further, the hospitals
indicated that they would recommend their alternative technology as a
method of medical waste treatment.
The potential hazards associated with medical waste treatment arise
primarily from the presence and handling of infectious waste.
Therefore, the potential hazards of medical waste treatment are similar
for operators of all medical waste treatment technologies, including
MWI. Few, if any, additional hazards are associated with alternative
technologies that have not already been associated with medical waste
incineration.
III. Regulatory Options and Impacts for Existing MWI
As discussed earlier, the MACT ``floor'' defines the least
stringent emission guidelines the EPA may adopt for existing MWI.
However, as also discussed earlier, the Clean Air Act requires the EPA
to examine alternative emission guidelines (i.e., regulatory options)
more stringent than the MACT floor. The EPA must consider the cost,
environmental, and energy impacts of these regulatory options and
select one that reflects the maximum reduction in
[[Page 31755]]
emissions that EPA determines is achievable (i.e., MACT).
At proposal, the EPA concluded all existing MWI would need good
combustion and dry scrubbers to meet the MACT floors for CO, PM, and
HCl. Consequently, EPA was left to consider only two regulatory options
for MACT. The first regulatory option reflected the floor (i.e.,
emission limitations achievable with good combustion and dry
scrubbers). The second reflected emission limitations achievable with
good combustion and dry scrubbers with activated carbon injection.
Based on the cost, environmental, and energy impacts of the second
regulatory option relative to the first option, EPA selected the second
option as MACT. Consequently, EPA proposed emission guidelines for
existing MWI based on the use of good combustion and dry scrubbers with
activated carbon injection.
As discussed earlier in this notice, EPA received numerous comments
containing substantial new information following proposal. Based on
this information, new conclusions concerning the MWI inventory, MWI
subcategories, performance of emission control technologies, MACT
floors, and monitoring and testing options have been reached. As a
result, EPA now believes there are several new regulatory options that
merit consideration in selecting MACT for existing MWI. The following
sections summarize these new regulatory options and the EPA's initial
assessment of their merits.
A. Regulatory Options
As discussed earlier, new MACT floor emission levels were developed
for small, medium, and large MWI. To assess the impacts of regulatory
options, EPA must first consider what emission control technology(s)
existing MWI may need to meet regulations based on these floor emission
limits. The floor for small existing MWI appears to require good
combustion; add-on wet scrubbing systems would not be necessary to meet
the MACT floor. For medium existing MWI, the MACT floor appears to
require good combustion and a moderate efficiency wet scrubber. The
MACT floor for large existing MWI appears to require good combustion
and a high efficiency wet scrubber.
Having identified these control technologies, the EPA is now able
to review the performance capabilities of other emission control
technologies and identify those that are capable of achieving even
greater emission reductions. This review enables EPA to identify
regulatory options more stringent than the floor that could be selected
as MACT.
For small existing MWI, as mentioned above, good combustion is the
emission control technology most MWI would probably need to meet the
MACT floor emission levels. Therefore, this technology serves as the
basis for the first regulatory option for the MACT emission guidelines
for small existing MWI. Based on the performance capabilities of
various emission control technologies, however, using low efficiency
wet scrubbing systems in addition to good combustion could achieve
greater emission reductions. This combination would achieve further
emission reductions in PM and dioxins, as well as HCl, Pb, Hg, and Cd.
Therefore, these controls used together are a possible option beyond
the MACT floor emission levels for small existing MWI.
As discussed earlier in Section II.B., the availability of
alternatives for the treatment and disposal of medical waste is
generally more limited in rural areas than in urban areas. Therefore,
the potential impact of MACT regulations on small existing MWI may be
greater in rural than in urban areas. This concern was expressed in
many comments EPA received following proposal. As also discussed
earlier in Section II.B., section 129 of the Clean Air Act permits EPA
to subcategorize the MACT emission guidelines by class, consequently,
subcategorizing small existing MWI into rural and urban classes was
examined. In terms of the MACT floor emission limits, however,
subcategorizing small existing MWI into rural and urban classes made no
difference--the MACT floor emission limits are the same. As a result,
for purposes of the MACT floor, there is no merit to subcategorizing
small existing MWI into rural and urban classes.
Although subcategorizing based on location was rejected for
purposes of the MACT floor, it was considered again in identifying
regulatory options more stringent than the MACT floor. Thus, the
regulatory option of MACT emission guidelines for small existing MWI
based on the use of good combustion and low efficiency wet scrubbing
systems was subdivided to create two options. The first regulatory
option beyond the MACT floor is to base the MACT guidelines for small
existing MWI located in rural areas on good combustion only, as
required by the MACT floor, but to base MACT guidelines for small
existing MWI located in urban areas on good combustion and low
efficiency wet scrubbing systems. If this option were selected as the
basis for the final MACT emission guidelines, the emission limits for
small existing MWI located in rural areas would be different than the
emission limits for small existing MWI located in urban areas.
As discussed in Section II.B., location, by itself, is not a valid
criterion for subcategorization under the Clean Air Act. In addition,
use of location as surrogate measure of the availability of technology
may not be a valid criterion for subcategorization either. There may be
statutory limitations to this approach. As a result, the previous
discussion regarding differences in regulatory requirements based on
the location of an MWI may not be allowed under the Clean Air Act, and
EPA specifically requests comment on the validity of this approach. As
discussed later in Section V., one of the options EPA is considering
would reflect good combustion and wet scrubbers on all small existing
MWI except where an individual MWI could meet certain ``criteria,'' in
which case the individual MWI would be subject to emission limits based
on good combustion alone. Consequently, in addition to seeking comment
on the validity of identifying urban and rural MWI as separate
``classes,'' EPA also requests comment on other criteria that could be
used to make distinctions in regulatory requirements.
A third regulatory option is MACT emission guidelines for small
existing MWI located in both rural and urban areas based on good
combustion and low efficiency wet scrubbing systems. In other words, no
difference in the MACT emission limits between small existing MWI
located in rural or urban areas would exist. This third option would
achieve greater emission reductions than the second option.
Beyond these three regulatory options (i.e., the MACT floor option
and the two options more stringent than the floor), a review of the
performance capabilities of various emission control technologies
readily identifies a fourth regulatory option for small existing MWI.
This regulatory option is to base the MACT emission guidelines for
small existing MWI on the use of good combustion and moderate
efficiency wet scrubbing systems. This regulatory option would further
reduce PM emissions, however, it would not achieve further reductions
in emissions of other pollutants. As summarized earlier, moderate and
high efficiency wet scrubbing systems do not appear to achieve greater
emission reductions of dioxins, acid gases (e.g., HCl), or the metals
(i.e., Hg, Pb, or Cd) than low efficiency wet scrubbing systems.
[[Page 31756]]
Option 4 could also be subdivided into two options: (1) MACT
emission guidelines for small existing MWI in rural areas based on good
combustion and low efficiency wet scrubbing systems; and MACT
guidelines for small existing MWI in urban areas based on good
combustion and moderate efficiency wet scrubbing systems and (2) MACT
emission guidelines for small existing MWI in both rural and urban
areas based on good combustion and moderate efficiency wet scrubbing
systems. However, the cost difference between using a low efficiency
wet scrubbing system or a moderate efficiency wet scrubbing system is
not as great as that between using a low efficiency wet scrubbing
system or not using a wet scrubbing system at all. Consequently, at
this point, to limit the number of regulatory options under
consideration, the EPA has chosen not to further subdivide this
regulatory option.
Reviewing the performance capabilities of emission control
technologies identifies a fifth regulatory option for small existing
MWI. This option is to base the MACT emission guidelines for small
existing MWI on the use of good combustion and high efficiency wet
scrubbing systems. This would further reduce PM emissions, but as
outlined above, would not further reduce emissions of other air
pollutants such as dioxins, acid gases (e.g., HCl), or the metals
(i.e., Pb, Hg, Cd).
A sixth regulatory option for small existing MWI also is apparent.
This option is to base the MACT emission guidelines for small existing
MWI on the use of good combustion and dry scrubbing systems with
activated carbon injection. This possibility would further reduce
emissions of Pb, Cd, and dioxins, but would not further reduce
emissions of other air pollutants. Dry scrubbing systems, however,
generally cost about one and a half times what high-efficiency wet
scrubbing systems cost to operate annually, and the overall difference
in the emissions control performance between the two systems is
relatively small. Therefore, at this point, to limit the total number
of regulatory options under consideration, the EPA has chosen not to
include this sixth regulatory option for small existing MWI.
For medium existing MWI, as discussed earlier, the use of good
combustion and moderate efficiency wet scrubbing systems appears to be
necessary to meet the MACT floor emission limits. This option,
therefore, is the first regulatory option for medium existing MWI. The
second regulatory option is to base the emission guidelines on good
combustion and high efficiency wet scrubbing systems.
Finally, for large existing MWI, as discussed earlier, the use of
good combustion and high efficiency wet scrubbing systems appears to be
necessary to meet the MACT floor emission limits. Thus, the EPA is not
inclined at this point to consider other regulatory options for large
existing MWI.
As mentioned above, a review of the performance capabilities of
emission control technologies indicates that dry scrubbing systems can
reduce emissions of some pollutants (i.e., Pb, Cd, and dioxins) greater
than high-efficiency wet scrubbing systems. Additional regulatory
options for both medium and large existing MWI could be structured,
therefore, around the use of dry scrubbing systems. However, as also
mentioned above, the cost of these systems is much higher than that of
high-efficiency wet scrubbing systems and the overall difference in
emission control performance is relatively small. For existing MWI
already equipped with wet scrubbers, replacing a wet scrubber with a
dry scrubber would be exorbitantly expensive. As a result, at this
point, the EPA has chosen not to develop additional regulatory options
for medium and large existing MWI based on the use of dry scrubbing
systems to keep the total number of regulatory options under
consideration to a manageable number.
The regulatory options outlined above are compiled in Table 13.
This table summarizes the technology basis for the regulatory options
for the various MACT emission guidelines the EPA believes merit
consideration as MACT for existing MWI. This table is constructed only
to organize and structure an analysis of the cost, environmental, and
energy impacts associated with the various MACT emission guidelines in
order to consider these impacts in selecting MACT for existing MWI. In
reviewing this table, therefore, there are several important points to
keep in mind.
Table 13.--Level of Air Pollution Control Associated With Each Regulatory Option for Existing MWI
--------------------------------------------------------------------------------------------------------------------------------------------------------
Regulatory options
MWI size -----------------------------------------------------------------------------------------------------------------------
1 2 3 4 5 6
--------------------------------------------------------------------------------------------------------------------------------------------------------
Small 200 lb/hr...... Good combustion... Good combustion on Good combustion Good combustion Good combustion Good combustion
rural; Good and low and moderate and moderate and high
combustion and efficiency wet efficiency wet efficiency wet efficiency wet
low efficiency scrubber. scrubber. scrubber. scrubber.
wet scrubber on
urban.
Medium 201-500 lb/hr............ Good combustion Good combustion Good combustion Good combustion Good combustion Good combustion
and moderate and moderate and moderate and moderate and high and high
efficiency wet efficiency wet efficiency wet efficiency wet efficiency wet efficiency wet
scrubber. scrubber. scubber. scrubber. scrubber. scrubber.
Large 500 lb/hr................. Good combustion Good combustion Good combustion Good combustion Good combustion Good combustion
and high and high and high and high and high and high
efficiency wet efficiency wet efficiency wet efficiency wet efficiency wet efficiency wet
scrubber. scrubber. scubber. scrubber. scrubber. scrubber.
--------------------------------------------------------------------------------------------------------------------------------------------------------
First, the MACT emission guidelines for existing MWI will not
include requirements to use a specific emission control system or
technology; the MACT emission guidelines will only include emission
limits, which may be met by any means or by using any control system or
technology the owner or operator of the MWI decides to use to meet
these emission limits. Second, to the extent possible (i.e., within the
constraints imposed by Section 129 of the Clean Air Act), the EPA plans
to adopt emission limits in the MACT emission guidelines that can be
met through the use of several emission control systems or
technologies. Consequently, where not constrained by
[[Page 31757]]
the Clean Air Act, the actual emission limits associated with some of
the regulatory options shown in Table 13 have been selected at a level
designed to encourage or permit the use of both wet and dry scrubbing
control systems, as outlined below.
The emission limits associated with each of the regulatory options
for small, medium, and large existing MWI are presented in Table 14.
Table 14.--Emission Limitations Associated With Each Regulatory Option for Small, Medium, and Large Existing MWI
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Regulatory
Pollutant, units options Small MWI's Medium MWI's Large MWI's
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1 2 (rural) 2 (urban)........ 3................ 4 and 5......... 6............... 1-4............. 5 and 6......... 1-6
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PM, gr/dscf..................... 0.086 0.086 0.05............. 0.05............. 0.03............ 0.015........... 0.03............ 0.015........... 0.015.
CO, ppmdv....................... 40 40 40............... 40............... 40.............. 40.............. 40.............. 40.............. 40.
CDD/CDF, ng/dscm................ 800 800 125.............. 125.............. 125............. 125............. 125............. 125............. 125.
TEQ CDD/CDF, ng/dscm............ 15 15 2.3.............. 2.3.............. 2.3............. 2.3............. 2.3............. 2.3............. 2.3.
HCI, ppmdv...................... 3,100 3,100 100 or 93%....... 100 or 93%....... 100 or 93%...... 100 or 93%...... 100 or 93%...... 100 or 93%...... 100 or 93%.
SO2, ppmdv...................... 55 55 55............... 55............... 55.............. 55.............. 55.............. 55.............. 55.
NOx, ppmdv...................... 250 250 250.............. 250.............. 250............. 250............. 250............. 250............. 250.
Pb, mg/dscm..................... 10 10 1.2 or 70%....... 1.2 or 70%....... 1.2 or 70%...... 1.2 or 70%...... 1.2 or 70%...... 1.2 or 70%...... 1.2 or 70%.
Cd, mg/dscm..................... 4 4 0.16 or 65%...... 0.16 or 65%...... 0.16 or 65%..... 0.16 or 65%..... 0.16 or 65%..... 0.16 or 65%..... 0.16 or 65%.
HG, mg/dscm..................... 7.5 7.5 0.55 or 85%...... 0.55 or 85%...... 0.55 or 85%..... 0.55 or 85%..... 0.55 or 85%..... 0.55 or 85%..... 0.55 or 85%.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Regulatory Option 1 in Table 14 reflects the performance of the
emission control system or technology needed to meet the MACT floor.
For small existing MWI, Regulatory Option 1 reflects emission limits
based on good combustion. For medium existing MWI, Regulatory Option 1
reflects emission limits based on good combustion and moderate
efficiency wet scrubbers, except for HCl (discussed below). For large
existing MWI, Regulatory Option 1 reflects emission limits based on
good combustion and high efficiency wet scrubbers, except for HCl
(discussed below).
Dry scrubbers with activated carbon injection can achieve the
emission limits associated with moderate or high efficiency wet
scrubbers, with the exception of HCl. While dry scrubbers cannot reduce
HCl emissions to the same levels as wet scrubbers, dry scrubbers can
achieve the MACT floor emission level for HCl. Consequently, Regulatory
Option 1 reflects the HCl emission limit achievable with a dry scrubber
for both medium and large existing MWI. Both technologies (wet or dry
scrubber) are capable of achieving the emission limits shown for
Regulatory Option 1.
Regulatory Option 2 is the same as Regulatory Option 1 for medium
and large existing MWI. Small existing MWI located in urban areas would
be required to meet emission limits associated with good combustion and
low efficiency wet scrubbers. Small existing MWI located in rural areas
would remain subject to the same emission limits as Regulatory Option 1
(based on good combustion). Regulatory Option 3 would establish
emission limits for all small existing MWI (urban and rural) based on
good combustion and low efficiency wet scrubbers. Regulatory Option 4
would establish emission limits for all small existing MWI based on
good combustion and moderate efficiency wet scrubbers. Requirements for
medium and large existing MWI would remain the same under Regulatory
Options 1, 2, 3, and 4. As discussed above, HCl emission limits in all
cases would allow the use of dry scrubbers.
Regulatory Option 5 would establish emission limits for small
existing MWI based on good combustion and moderate efficiency wet
scrubbers; medium existing MWI based on good combustion and high
efficiency wet scrubbers; and large existing MWI based on good
combustion and high efficiency wet scrubbers. The sixth and final
regulatory option would require all existing MWI to meet emission
limitations associated with good combustion and high efficiency wet
scrubbers. As discussed above, the HCl emission limit under Regulatory
Options 5 and 6 would allow the use of dry scrubbing systems.
B. National Environmental and Cost Impacts
This section presents a summary of the air, water, solid waste,
energy, and cost impacts of the six regulatory options described above
for existing MWI. Economic impacts are discussed in Section III.C. All
impacts are nationwide impacts resulting from the implementation of the
emission guidelines on existing MWI.
1. Analytical Approach
As discussed at proposal and within this notice, healthcare
facilities may choose from among a number of alternatives for treatment
and disposal of their medical wastes; however, these alternatives are
generally more limited for healthcare facilities located in rural areas
than for those in urban areas. In fact, as stated at proposal, most
estimates are that less than half of hospitals today currently operate
onsite medical waste incinerators. The clear trend over the past
several years has been for more and more hospitals to turn to the use
of alternative onsite medical waste treatment technologies or
commercial offsite treatment and disposal services. Consequently, even
fewer hospitals are now likely to operate onsite medical waste
incinerators.
More than half of existing hospitals today, therefore, have chosen
to use other means of treatment and disposal of their medical waste
than operation of an onsite incinerator. This is a clear
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indication that alternatives to the use of onsite incinerators exist
and that they are readily available in many cases. (Although as
mentioned above, these alternatives--particularly the availability and
competitive cost of offsite commercial treatment and disposal
services--tend to be more limited in rural areas than in urban areas).
For other healthcare facilities, such as nursing homes, outpatient
clinics, doctors and dentists offices, etc., only very few facilities
currently operate onsite medical waste incinerators. Therefore, for
these types of healthcare facilities, the percentage of such facilities
using alternative means of treatment and disposal of medical waste--
particularly commercial treatment and disposal services--is much
higher, probably higher than 95 percent. This high percentage is
further confirmation of the availability of alternatives to onsite
incinerators for the treatment and disposal of medical waste.
A very likely reaction and outcome associated with the adoption of
MACT emission guidelines for existing MWI, therefore, is an increase in
the use of these alternatives by healthcare facilities for treatment
and disposal of medical waste. The EPA's objective is not to encourage
the use of alternatives or to discourage the continued use of onsite
medical waste incinerators; the EPA's objective is to adopt MACT
emission guidelines for existing MWI that fulfill the requirements of
Section 129 of the Clean Air Act. In doing so, however, one outcome
associated with adoption of these MACT emission guidelines is likely to
be an increase in the use of alternatives and a decrease in the
continued use of onsite medical waste incinerators. Consequently, EPA
should acknowledge and incorporate this outcome into the analyses of
the cost, environmental, and energy impacts associated with the MACT
emission guidelines.
In these analyses of the cost, environmental, and energy impacts,
the selection of an alternative form of medical waste treatment and
disposal by a healthcare facility, rather than the operation of an
onsite medical waste incinerator and purchase the emission control
technology necessary to meet the MACT emission limits, is referred to
as ``switching''. Switching was incorporated in the analyses at
proposal and was the basis for the conclusion at proposal that adoption
of the proposed MACT emission guidelines could lead to as many as 80
percen
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