[Federal Register Volume 59, Number 175 (Monday, September 12, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-22133]
[[Page Unknown]]
[Federal Register: September 12, 1994]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 60
[AD-FRL-5068-3]
RIN 2060-AE94
Standards of Performance for New Stationary Sources: Volatile
Organic Compound (VOC) Emissions From the Synthetic Organic Chemical
Manufacturing Industry (SOCMI) Wastewater
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule and notice of public hearing.
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SUMMARY: This action proposes standards of performance for wastewater
sources in the Synthetic Organic Chemical Manufacturing Industry
(SOCMI). These standards implement section 111 of the Clean Air Act
(the ACT) and are based on the Administrator's determination that VOC
emissions from SOCMI cause, or contribute significantly to, air
pollution that may reasonably be anticipated to endanger public health
or welfare. The intended effect of these standards is to require all
new, modified, and reconstructed SOCMI process units to control
wastewater emissions to the level achievable by the best demonstrated
system of continuous emission reduction, considering costs, nonair
quality health, environmental, and energy impacts, not just with end-
of-pipe and add-on controls, but also by eliminating or reducing the
formation of these pollutants. The proposed regulation would achieve an
estimated reduction of 16,200 megagrams (Mg) of VOC in the fifth year
following promulgation.
DATES: Comments. The EPA will accept comments on the proposed rule
until November 14, 1994.
Public Hearing. If requested, the EPA will hold a public hearing
concerning the proposed rule beginning at 10 a.m. on October 12, 1994.
Persons interested in presenting oral testimony to the EPA at a public
hearing must contact the person listed below (see FOR FURTHER
INFORMATION CONTACT) no later than September 27, 1994. Persons
interested in attending the hearing should call the person listed below
(see FOR FURTHER INFORMATION CONTACT) to verify that a hearing will be
held.
ADDRESSES: Comments. Interested parties may submit written comments
regarding the proposed rule (in duplicate, if possible) to Docket No.
A-94-32 at the following address: U.S. Environmental Protection, Air
Docket Section (6102), 401 M Street, SW, Washington, DC 20460. The EPA
requests that a separate copy of the comments also be sent to the
contact person listed below (see FOR FURTHER INFORMATION CONTACT).
Public Hearing. The public hearing will be held at the EPA Office
of Administration Auditorium, Research Triangle Park, North Carolina.
Docket. Docket No. A-94-32 contains supporting information used in
developing the proposed standards. The docket is located at the above
address in Room M-1500, Waterside Mall (ground floor), and may be
inspected from 8:30 a.m. to noon, and 1 to 3 p.m., Monday through
Friday. The proposed regulatory text, Background Information Document,
and other materials related to this document are available for review
in the docket. Copies of this information may be obtained by request
from the Air Docket by calling (202) 260-7548. A reasonable fee may be
charged for copying docket materials.
FOR FURTHER INFORMATION CONTACT: Mr. Robert Lucas, Office of Air
Quality Planning and Standards, Chemicals and Petroleum Branch (MD-13),
U.S. Environmental Protection Agency, Research Triangle Park, North
Carolina, 27711, telephone (919) 541-0884.
SUPPLEMENTARY INFORMATION: Additional Detailed Information. The
proposed regulatory text and the Background Information Document are
not included in this Federal Register document, but are available in
Docket No. A-94-32 or by request from the Air Docket (see ADDRESSES).
This notice, the proposed regulatory text, and the background
information document are also available on the Technology Transfer
Network (TTN), one of the EPA's electronic bulletin boards. 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 up to a 14,400 bauds per second
modem. If more information on TTN is needed, call the HELP line at
(919) 541-5384. A diskette containing the preamble, regulation, and
background information document will be supplied by faxing the request
to (919) 540-3470 with name, address, and phone number.
The following outline is provided to aid in reading the preamble
for the proposed standards.
I. Introduction
A. New Source Performance Standards--General
B. NSPS Decision Scheme
II. Summary of the Proposed NSPS
A. Source Category to be Regulated
B. Pollutants to be Regulated
C. Best Demonstrated Technology
D. Affected Facility
E. Emission Points to be Regulated
F. Format for the Standards
G. Proposed Standards
H. Modification and Reconstruction
I. Compliance Testing
J. Monitoring Requirements
K. Reporting and Recordkeeping
III. Impacts of the Proposed NSPS
A. Environmental Impacts
B. Cost Impacts
C. Economic Impacts
IV. Rationale for Proposed Standards
A. Selection of Source Category
B. Selection of Emission Sources
C. Pollutants To Be Regulated
D. Selection of Affected Facility
E. Selection of Best Demonstrated Technology
F. Selection of Format of Proposed Standard
G. Selection of Standards
H. Modification and Reconstruction Considerations
I. Monitoring Requirements
J. Performance Test Methods
K. Reporting and Recordkeeping Requirements
L. Solicitation of Comments
V. Administrative Requirements
A. Public Hearing
B. Administrative Designation and Regulatory Analysis
C. Compliance With Regulatory Flexibility Act
D. Paperwork Reduction Act
I. Introduction
A. New Source Performance Standards--General
New source performance standards (NSPS) implement section 111 of
the Act. The NSPS are issued for categories of sources that cause, or
contribute significantly to, air pollution that may reasonably be
anticipated to endanger public health or welfare. They apply to new
stationary sources of emissions, i.e., sources whose construction,
reconstruction, or modification begins after a standard for them is
proposed.
An NSPS requires these sources to control emissions to the level
achievable by ``best demonstrated technology,'' or ``BDT.''
B. NSPS Decision Scheme
An NSPS is the product of a series of decisions made during
development of the regulation. Elements in this ``decision scheme''
include the following:
1. Source category to be regulated: usually an entire industry, but
can be a process or group of processes within an industry.
2. Pollutant(s) to be regulated: the particular substance(s)
emitted by the source that the standard will control.
3. Best demonstrated technology: the technology on which the Agency
will base the standards, as defined in section 111(a)(1) of the Act.
4. Affected facility: the pieces or groups of equipment that
comprise the sources to which the standards will apply.
5. Emission points to be regulated: within the affected facility,
the specific physical location emitting pollutants (e.g., vents,
equipment leaks, and wastewater streams).
6. Format for the standards: the form in which the standards are
expressed, i.e., as a percent reduction in emissions, as pollutant
concentration, or as equipment standards.
7. Standards: based on what BDT can achieve, the maximum
permissible emissions, or design, equipment, work practice, or
operational requirements if emission limits are infeasible.
8. Other considerations: in addition, NSPS usually include
modification/reconstruction considerations, monitoring requirements,
performance test methods, and reporting and recordkeeping requirements.
II. Summary of the Proposed NSPS
A. Source Category To Be Regulated
Volatile organic compound emissions from SOCMI wastewater (also
referred to as ``secondary sources'') are being regulated under section
111 of the Act. The proposed standards would regulate VOC emissions
from wastewater generated by SOCMI process units and are limited to
emission points in the associated process unit's wastewater collection
and treatment systems. Specific emission points are discussed in
section II.E.
Wastewater is water that comes in contact with process fluids
during manufacturing, processing, or maintenance operations within a
process unit at a SOCMI facility. Most wastewaters contain relatively
low concentrations of contaminants (e.g., less than 2 percent or 20,000
parts per million (ppm)) and are managed in wastewater collection and
treatment systems. Wastewater collection and treatment systems
typically include individual drain systems, oil- water separators, air
flotation units, equalization tanks, and biological treatments units.
Volatile organic compounds are emitted from the wastewater during
collection and treatment.
Regulations targeting emissions from SOCMI wastewater have been
developed previously. National emission standards for hazardous air
pollutants (NESHAP) for benzene waste operations (40 CFR part 61,
subpart FF) regulate benzene emissions from SOCMI waste streams that
contain benzene at concentrations of 10 parts per million by weight
(ppmw) or more at facilities that handle at least 10 Mg/yr of benzene
in certain wastes. A second regulation, the hazardous organic NESHAP
(``the HON'') in subpart G of 40 CFR part 63, is broader in scope,
regulating emissions of many organic hazardous air pollutants (HAP)
from SOCMI wastewater. The HON imposes standards on SOCMI process
wastewater streams from process units that produce any of a selected
group of products at facilities that are major sources under the Act.
The rule covers individual waste streams that contain one or more of
the HAP identified in section 112(b) of the Act at concentrations above
specified levels. Generally, a SOCMI source subject to the benzene
waste NESHAP would also be subject to the HON.
A third regulation that may affect the chemical industry is the
Resource Conservation and Recovery Act (RCRA) air emission standards
for hazardous waste treatment, storage, and disposal facilities. That
rule will establish standards for controlling emissions from wastes
that are identified as hazardous under RCRA at facilities subject to
subtitle C permitting requirements. Under that rule, hazardous wastes
would have to be managed in controlled units until the waste is treated
to remove or destroy certain hazardous components. The rule only
applies to units and facilities that are permitted under RCRA subtitle
C. However, under RCRA, wastewater treatment units are not subject to
subtitle C hazardous waste management standards provided the unit is
part of a wastewater treatment facility that is subject to regulation
under either section 402 or 307(b) of the Clean Water Act. Thus,
hazardous waste tank systems that are used to store or treat wastewater
that is managed at an on-site wastewater treatment facility with a
National Pollution Discharge Elimination System permit or that
discharges to a publicly- owned treatment works would generally be
exempt from the RCRA regulations.
In addition to the HON, the benzene waste NESHAP, and the RCRA air
standards, section 182(b)(2) of the Act requires that State
implementation plans (SIP's) for certain ozone nonattainment areas be
revised to require the implementation of reasonably available control
technology (RACT) for control of VOC emissions. The EPA has defined
RACT generally as the lowest emission limitation that a particular
source is capable of meeting by the application of control technology
that is reasonably available, considering technological and economic
feasibility. In some cases, the EPA has, or will, issue guidance
relative to RACT in the form of a control techniques guidelines (CTG)
document. A draft of the Industrial Wastewater (IWW) CTG was released
for public comment on December 29, 1993. The SOCMI is a subset of the
industry group which is covered by the IWW CTG. The CTG is intended to
provide State and local air pollution authorities with an information
base for proceeding with their own analysis of RACT to meet statutory
requirements. Due to time and budget constraints, the IWW CTG has not
been finalized. An alternative control technology (ACT) document has
been prepared and provided to the States as interim guidance to aid in
development of rules in the absence of the final IWW CTG.
In spite of the guidance and the three separate rules to regulate
emissions from wastewater streams at SOCMI facilities, there are
substantial gaps in the extent to which these rules control emissions
from SOCMI wastewater streams with the potential to emit VOC. The HON
applies to only a segment of the industry that produces a specified set
of products, which does not include all SOCMI installations. In
addition, the HON only regulates streams that contain HAP at
concentrations above a trigger level. Consequently, the HON does not
regulate wastewater streams that emit VOC that are not HAP. The benzene
waste NESHAP applies to all SOCMI installations but is very limited in
scope regarding the waste streams regulated, i.e., only those streams
that contain benzene are subject to the rule. Many of the wastewater
streams at SOCMI plants do not contain benzene but do contain other VOC
that are emitted to the atmosphere if left uncontrolled. The RCRA air
standards for hazardous waste toxic storage and disposal facilities are
not expected to impact a significant number of wastewater streams at
SOCMI plants because of the wastewater exemption under RCRA that was
discussed above.
The EPA analysis of SOCMI wastewater data submitted by industry
shows a significant number of wastewater streams generated by SOCMI
process units will not be regulated by the HON or other wastewater
related rules. This is in large part a result of the fact that the
source category coverage for the SOCMI Wastewater NSPS is considerably
broader than that of the HON. For example, the chemical list defining
the affected SOCMI process units is nearly twice as large for the NSPS
as for the HON. For many of the SOCMI industries, VOC-containing
wastewater streams do not contain HAP and therefore controlling only
HAP-containing streams, as is required under the HON, would not
substantially reduce VOC emissions. It is estimated that 68 percent of
all new SOCMI chemical production process units will have wastewater
streams that would require control under the proposed NSPS but will not
require control under the HON.
This NSPS for SOCMI wastewater sources is needed to fill the gaps
in the coverage of VOC emissions from wastewater streams left uncovered
by other regulations. In addition, the benzene waste NESHAP and the
RCRA air standards are risk-based standards. Risk-based standards are
designed to reduce emissions to a level that will protect human health
and the environment with an ample margin of safety. The goal of an
NSPS, on the other hand, is to improve ambient air quality over time by
application of best demonstrated technology (BDT) on all new, modified,
or reconstructed sources. The goal of the CTG is to provide guidance to
States in revising their SIP's and to help bring their nonattainment
areas into compliance with the National Ambient Air Quality Standards.
The SIP rules do not apply at facilities that are in ozone attainment
areas. Furthermore, NSPS require installation of BDT rather than RACT,
which in some cases may achieve a higher level of emission reduction.
The NSPS would impose consistent, nationwide regulatory requirements,
which would ensure that waste streams and wastewater streams at all
new, modified, and reconstructed SOCMI process units are controlled in
a consistent manner using the best emission controls.
In summary, although a portion of waste streams and wastewater
streams at SOCMI sites are already controlled as a result of existing
and planned regulations, none of these regulations cover all SOCMI
waste streams with the potential to emit VOC. These other regulations
are limited in scope and leave some wastewater streams uncontrolled for
air emissions. These uncontrolled wastewater streams are the subject of
the NSPS for SOCMI wastewater sources.
It is possible that there may be some overlap among those
regulations affecting wastes and wastewater at SOCMI facilities,
leading to possibly duplicative requirements. In order to avoid the
burden of such duplication, the EPA is proposing in the SOCMI NSPS that
the owner or operator of waste management units, treatment processes,
or control devices affected by the proposed rule may comply with the
control requirements of the proposed rule by demonstrating compliance
with the benzene waste operations NESHAP, the HON, or the RCRA air
emission standards for hazardous waste treatment, storage, and disposal
facilities. The owner or operator would also be required to maintain
records documenting which regulation is being used to demonstrate
compliance with the proposed NSPS. An owner or operator who chooses to
demonstrate compliance in this manner would be exempted from the
inspection, monitoring, reporting, and recordkeeping requirements of
the proposed rule that relate to the affected waste management unit,
treatment process, or control device. The Agency is soliciting comments
on the proposed approach to reducing the regulatory burden for these
sources. In addition, the Agency is interested in receiving information
on the level of burden that would be imposed by the possible
duplication of requirements.
B. Pollutants To Be Regulated
The air pollutant to be regulated by these standards is VOC. The
primary air pollutant from SOCMI wastewater facilities is VOC, which is
a precursor to the formation of ozone and oxygenated organic aerosols.
C. Best Demonstrated Technology
Section 111 of the Act states that NSPS ``shall reflect the degree
of emission limitation and the percentage reduction achievable through
application of the best technological system of continuous emission
reduction which (taking into consideration the cost of achieving such
emission reduction, any nonair quality health and environmental impact
and energy requirements) the Administrator determines has been
adequately demonstrated.'' The technology basis for NSPS that meets
these criteria is referred to as ``best demonstrated technology
(BDT).'' In the standards development process for NSPS, BDT should be
identified, the performance of BDT established, and a regulatory
alternative selected that will require the use of BDT or an equivalent
technology.
Volatile organic compound emissions from wastewater can be
effectively reduced with the following control approach: (1) Identify
wastewater streams with significant VOC emission potential; (2) recycle
or treat those wastewater streams to remove their potential for
emissions; (3) prior to treatment or recycling, manage those waste
streams in units equipped with air emission controls; (4) recycle any
treatment residuals or treat any residuals to destroy the VOC; and (5)
control air emissions generated by treatment processes.
The treatment technology that is the basis for the proposed
standards for wastewater is steam stripping, a proven treatment
technology for wastewaters generated within the targeted industry. It
is generally applicable to wastewater streams with the potential to
emit VOC and, in general, achieves the highest VOC emission reduction
among demonstrated VOC control technologies. Facilities can comply by
installing the design steam stripper or by installing a stripper or
other treatment device that achieves an equivalent VOC emission
reduction. Control of air emissions from the stripper and from
treatment residuals is also required. Although standards for wastewater
are based on the performance of steam stripping, other treatment
technologies such as biodegradation have also been demonstrated to be
effective. To be considered equivalent to steam stripping, a properly
operated biological treatment unit must achieve a 95-percent VOC
reduction or meet the required mass removal while controlling air
emissions. Biodegradation may also be used as one of a series of
treatment processes (e.g., a steam stripper followed by a biological
treatment unit) where the combination achieves a reduction of 99
percent or more in volatile organic concentration. Alternative
treatment technologies other than biodegradation are permitted if their
performance equals or exceeds that of steam stripping, i.e., a 99-
percent VOC reduction.
D. Affected Facility
For the SOCMI wastewater NSPS, the affected facility will be each
new process unit (and the wastewater streams it generates) at a SOCMI
plant. A SOCMI process unit will be defined as one producing one or
more of the chemicals listed in the regulation. A process unit at a
SOCMI plant will be considered to be new if construction, modification,
or reconstruction of the unit commences after the date the NSPS is
proposed in the Federal Register.
E. Emission Points to be Regulated
The air emission points selected for the proposed regulations
include all significant points in SOCMI process unit wastewater
collection and treatment systems that manage process or maintenance
wastewater streams or residuals generated from SOCMI process units that
produce any of the listed chemicals. The air emission release points in
the process unit wastewater collection and treatment system include
individual drain systems, which are comprised of equipment such as open
trenches, drains, manholes, junction boxes, lift stations, and weirs;
surface impoundments; wastewater storage and treatment tanks; oil-water
separators; containers; clarifiers; and biological treatment units. At
these release points, VOC can be transferred from the process unit
wastewater stream to the air.
F. Format for the Standards
As authorized under section 111 of the Act, the proposed standards
consist of a combination of emission standards and equipment, design,
and work practice standards. Emission standards are used whenever
feasible; however, such standards are not feasible in all
circumstances. In some cases, alternative emission standards are also
proposed. Separate standards for tanks, surface impoundments,
containers, individual drain systems, oil-water separators, treatment
processes, and control devices are proposed.
G. Proposed Standards
Under the proposed standards, SOCMI process unit wastewater streams
with a volatile organic concentration (measured using Reference Method
25D, 40 CFR part 60, appendix A) greater than or equal to 500 ppmw and
flow rates greater than or equal to 1.0 liter per minute (Lpm) are
required to be controlled. In addition, any wastewater stream with a
volatile organic concentration greater than 10,000 ppmw would be
controlled under the regulation, regardless of flow rate. Process units
that generate wastewater with a total annual volatile organic mass of
less than 1 Mg are exempt from the wastewater control requirements of
the proposed rule.
The proposed wastewater treatment standard involves the application
of a controlled collection and treatment system to individual
wastewater streams that fail the cut off criteria. The treatment
requirements are designed to reduce the VOC content in the wastewater
prior to placement in units without air emission controls. The proposal
includes a variety of compliance options in order to meet the treatment
process standard. These include a recycling option involving recycling
of the wastewater to a process unit, an equipment design and operation
standard, a numerical emission standard formatted as an effluent
concentration limit, and a numerical emission standard format in terms
a mass removal requirement.
Prior to treatment, the wastewater must be managed in units
equipped with air emission controls, and wastewater collection and
treatment systems must be designed and operated without leaks, as
defined in the standards. Following is a summary of the specific
standards for each of the individual types of SOCMI wastewater units.
1. Standards for Tanks
Under the proposed standards, owners and operators would be
required, with two exceptions, to place wastewater streams in one of
the following types of tanks depending on the tank capacity and vapor
pressure of the stored material: (1) A tank equipped with a cover
(e.g., a fixed roof) and a closed vent system and control device that
meets certain design, inspection, and measurement specifications
specified in the rules; (2) a tank equipped with a fixed roof and
internal floating roof that meets the design requirements specified
under the existing volatile organic liquid (VOL) storage NSPS (40 CFR
part 60, subpart Kb); (3) a tank equipped with an external floating
roof that meets the design, inspection, and measurement requirements
specified under the existing VOL storage NSPS; or (4) a pressure tank
that is designed and operated with no pressure releases during normal
operations including waste loading and unloading.
The proposed rules would provide two exceptions to the tank control
requirements described above. First, when an affected stream (i.e., one
in which the wastewater has a mass-weighted average volatile organic
concentration equal to or greater than 500 ppmw) is managed in certain
size tanks and possesses certain vapor pressure characteristics, an
owner or operator would be allowed to place the waste in a tank
equipped with a fixed roof. Second, when the waste is placed in a
biological treatment tank that meets the biological organic degradation
performance requirements (i.e., 95-percent destruction efficiency), no
additional air emission controls would be required.
Each cover opening not vented to a control device would be required
to be maintained in a closed, sealed position except at those times
when a specific opening is used to add, remove, inspect, or sample the
waste in the tank or to inspect, maintain, repair, or replace equipment
located underneath the cover. Safety devices that vent directly to the
atmosphere could be used on the cover or closedvent system with control
device provided that the safety device is not used for planned or
routine venting of organic vapors and the safety device remains in a
closed, sealed position at all times except when an unplanned event
requires the opening of the device.
2. Standards for Surface Impoundments
The owner or operator of an affected surface impoundment is
required to install and use emission control equipment. The proposed
rules would require owners or operators to place waste in a surface
impoundment equipped with a cover (e.g., air-supported structure) and a
closed- vent system with control device or, when applicable, a surface
impoundment equipped with a floating membrane cover as the air emission
control. If the surface impoundment is used for biological treatment
that meets the same organic biodegradation performance requirements
described above for tanks, no additional air emission controls would be
required to be used on the surface impoundment. The proposed operating
and venting requirements for surface impoundment air emission control
equipment are consistent with the rule requirements for tanks.
3. Standards for Containers
The proposed standards would not apply to a container that has a
design capacity less than or equal to 0.1 cubic meter (m3) (26.4
gallons (gal)). The owner or operator of an affected container would be
required to place the waste material either into a container equipped
with a cover that operates with no detectable organic emissions when
all openings are secured in a closed, sealed position or to meet the
alternative requirements discussed below.
Alternative requirements under the proposed standards for a drum
with a design capacity less than or equal to 0.42 m3 (110 gal)
would allow an owner or operator to place the waste in a drum meeting
the Department of Transportation (DOT) specifications and testing
requirements under 49 CFR part 178. For a drum meeting these DOT
regulations, neither Method 21 of 40 CFR part 60, appendix A, leak
monitoring, nor recordkeeping of cover design documentation is required
under the proposed standards.
Another alternative for containers under the proposed standards
would require the owner or operator of any container that attaches to
or forms a part of any truck, trailer, or rail car to show that the
container has been tested for organic vapor tightness within the
preceding 12 months in accordance with the requirements of Method 27 of
40 CFR part 60, appendix A. Method 27 is a pressure test procedure
originally developed by the EPA for determining the vapor-leak
tightness of a tank truck into which gasoline is placed. The EPA also
considers the use of Method 27 to be appropriate for determining vapor-
leak tightness of trucks, trailers, and rail cars into which wastes
containing volatile organics are placed. Neither Method 21, leak
monitoring, nor recordkeeping of cover design documentation is required
for trucks, trailers, or rail cars complying with this provision of the
rules.
If a waste is loaded into a container by pumping, the proposed
standards would require submerged fill of waste only into those
containers with a capacity equal to or greater than 0.42 m3 (110
gal). Accordingly, drums with design capacities up to and including
0.42 m3 (110 gal) are not required to be loaded by submerged fill.
When it is necessary for a container to be open during certain
treatment processes, the proposed standards would require the container
to be located in an enclosure connected to a closed-vent system with
control device. The enclosure would be required to be designed to
operate with sufficient airflow into the structure to capture all
organic vapors vented from the container and route the vapors through
the closed-vent system to the control device. The enclosure could have
permanent or temporary openings to allow worker access, passage of
containers through the enclosure by conveyor or other mechanical means,
or entry of permanent mechanical or electrical equipment, or to direct
airflow into the enclosure.
4. Standards for Individual Drain Systems
The proposed rule would require individual drain systems to meet
one of two standards. In the first case, the owner or operator would
comply by operating and maintaining on each opening in the individual
drain system a cover and closed-vent system. The covers and all
openings and the closed-vent system would meet the leak detection
requirements, unless the system is operated and maintained under
negative pressure. The cover and all openings would be maintained in a
closed, sealed position at all times when affected wastewater or
residual is in the system except when it is necessary to use the
opening for sampling or removal, or for equipment inspection,
maintenance, or repair. Each individual drain system would be subject
to initial and semi-annual inspections for improper work practices and
control equipment failures.
Alternatively, individual drain system components would be required
to comply with equipment standards. Each drain would be equipped with
water seal controls or a tightly sealed cap or plug to eliminate air
flow through the system. Each junction box would be equipped with a
cover and emission controls. Each sewer line would be covered or
enclosed in a manner so as to have no visible gaps or crack in joints,
seals, or other emission interfaces. This equipment would be subject to
regular inspection requirements.
5. Standards for Oil-Water Separators
The proposed standards would require owners or operators to operate
and maintain either a fixed roof and closed-vent system that routes the
VOC vapors from the oil-water separator to a control device or a
floating roof. The fixed roof and all openings and the closed-vent
system would be maintained in accordance with the leak detection
requirements of the proposed rule, unless the system is operated and
maintained under negative pressure. As with standards for other waste
management units, each opening would be maintained in a closed, sealed
position except when it is necessary to use the opening for sampling or
removal, or for equipment inspection, maintenance, or repair.
Except in cases where it is impossible to operate a floating roof,
such as over the weir mechanisms, the owner or operator would have the
option of using a floating roof that meets the requirements of subpart
QQQ of 40 CFR part 60. The owner or operator would measure primary and
secondary seal gaps on a periodic basis as well as inspect the oil-
water separator for improper work practices and control equipment
failures.
6. Standards for Treatment Processes
The owner or operator would be required to treat each affected
wastewater or residual stream by one of the following methods:
(1) Recycle or return to a production process such that the
wastewater stream or residual is not exposed to the atmosphere and
ensure that intervening waste management units meet the applicable
requirements of the standards;
(2) Treat using a waste management unit that either is a design
steam stripper, reduces by 99 percent or more the total volatile
organic mass flow rate, reduces the average volatile organic
concentration to less than 50 ppmw and reduces the total volatile
organic mass by 95 percent, or achieves a required volatile organic
mass removal rate for combined or mixed streams; or
(3) Treat wastewater streams generated by an affected process unit
with a biological treatment unit that achieves 95 percent total
volatile organic mass removal.
If the treatment process or waste management unit is a properly
operated biological treatment unit that meets the mass removal (i.e.,
biodegradation) requirements, the biological treatment unit need not be
covered and vented to a control device. However, the owner or operator
of any other treatment process or waste management unit subject to the
applicable standards (for example, if the treatment process is a steam
stripper, air stripper, or thin-film evaporation unit) would be
required to cover and vent the unit through a closed-vent system to a
control device and meet the leak detection requirements, unless the
cover and vent are operated and maintained under negative pressure. In
addition, any openings must be kept closed at all times that an
affected wastewater stream or treatment residual is in the process or
unit, except during inspection and maintenance and unless the unit is a
properly operated biological treatment unit as defined by the
standards.
Each treatment process or waste management unit used to comply with
the treatment processes standards would be required to provide a design
analysis and supporting documentation of the operating characteristics
of the treatment process or waste management unit that is based on
operation at a representative wastewater stream flow rate and volatile
organic concentration under which it would be most difficult to
demonstrate compliance (i.e., when air emissions are expected to be
highest). Alternatively, the owner or operator may conduct performance
tests using the test methods and procedures specified in the proposed
rules to demonstrate compliance. In addition, all openings are subject
to periodic inspection and repair schedules and monitoring
requirements.
The proposed rule provides several exceptions to the standards for
treatment processes. The owner or operator is considered to be in
compliance with the treatment requirements and is exempt from the
demonstration that the treatment process achieves the required
conditions if the treatment process is one of the following: (1) A
hazardous waste incinerator for which the owner or operator has been
issued a final permit under 40 CFR part 70 and 40 CFR part 264, subpart
O, or (2) an industrial furnace or boiler burning hazardous waste for
which the owner or operator has been issued a final permit under 40 CFR
part 270 and 40 CFR part 266, subpart H or has certified compliance
with the interim status requirements of 40 CFR part 266, subpart H. In
addition, if the affected wastewater stream or residual is discharged
to an underground injection well for which the owner or operator has
been issued a final permit under 40 CFR part 270 and 40 CFR part 122,
the owner is considered in compliance with the treatment provisions.
7. Standards for Control Devices
The proposed standards would require that each control device
achieve at least a 95-percent reduction in the total organic content of
the vapor stream vented to the device or, in the case of an enclosed
combustion device, a reduction of the total organic content of the
vapor stream to a level less than or equal to 20 ppmw on a dry basis,
corrected to 3 percent oxygen, or provide a minimum residence time and
temperature as specified in the proposed standards. Flares would be
required to comply with the requirements in 40 CFR part 60, subpart A.
With certain exceptions (e.g., some boilers and process heaters and
flares), compliance would either be demonstrated through a design
analysis that addresses vent stream characteristics and control device
operating parameters or performance tests would be conducted using the
methods and procedures specified in the proposed rules. In addition,
each control device is subject to the enhanced monitoring and continued
compliance requirements of section 114(a) of the CAAA, as well as to
periodic inspection and specified repair periods.
The standards would not require the use of any specific type of
equipment or add-on control device. An owner or operator would be
allowed the flexibility of choosing the control device that can achieve
the performance requirements and is best suited for a control
application based on the types and characteristics of the particular
organic vapor stream. Furthermore, the standards would not require that
each affected waste management unit be vented to a separate control
device dedicated to that particular unit. Vent streams from several
units can be combined and discharged to a single control device that
achieves the required level of performance.
H. Modification and Reconstruction
Provisions of the proposed standards would apply to existing
facilities that are modified or reconstructed after the date of
proposal. It is possible that at some facilities, feedstock, catalyst,
or reactant substitutions; process equipment changes; or combinations
of these two classes of changes above could trigger the part 60 General
Provisions related to modification or reconstruction of facilities.
Changes of this nature are likely to require both equipment and process
changes as well as significant capital expenditures. See section IV.H
for a more detailed discussion of these considerations.
I. Compliance Testing
Test methods and procedures would be required to ensure compliance
with the standards proposed for SOCMI wastewater sources. The proposed
standards include requirements for demonstrating that an emission point
or wastewater stream is being controlled in compliance with control
requirements or would not be required to be controlled. Also included
are provisions for an initial test for no detectable emissions (i.e.,
leaks as defined in the standards) from tanks, containers, surface
impoundments, closed-vent systems, and process wastewater collection
and treatment systems.
Test methods are provided for use by the owner or operator in
determining applicability of the standards to a given wastewater
stream. The three variables of concern, annual wastewater quantity,
average total volatile organic concentration, and annual average
wastewater flow rate, may be determined using a variety of methods. For
example, the proposed standards include provisions that would allow a
SOCMI process unit owner or operator to use either direct measurement
or knowledge of the wastewater to determine the volatile organic
concentration of the wastewater. Direct measurements would be conducted
in accordance with the requirements of Method 25D in appendix A of 40
CFR part 60. Knowledge of the wastewater can be demonstrated by
material balances, records of chemical purchases, process
stoichiometry, or previous test results.
A determination of the volatile organic concentration or average
annual flow rate of a wastewater would be required by the proposed
standards only when a wastewater subject to the standards is placed in
a waste management unit that is not equipped with air emission controls
in accordance with the rules. The SOCMI process unit owner or operator
would not be required to determine the volatile organic concentration
or average annual flow rate of wastewater streams that are managed only
in units equipped with air emission controls in accordance with the
requirements of the proposed standard up to the point of ultimate
recycle, disposal, or discharge.
J. Monitoring Requirements
To ensure that emission control equipment is properly operated and
maintained, the proposed standards would require the owner or operator
to inspect and monitor certain air emission control equipment used to
comply with the rules. Enhanced monitoring of control device operation
is required under the proposed standards to demonstrate compliance with
the standards. This involves the use of automated instrumentation to
measure critical operating parameters that indicate whether the control
device is operating correctly or is malfunctioning. Failure to maintain
the established values of the monitored parameters would be an
enforceable violation of the emission limits of the standard.
In addition to the enhanced monitoring requirements, an initial
leak detection test using Method 21 under appendix A of 40 CFR part 60
is required for certain cover components to ensure gaskets and seals
are in good condition and for closed-vent systems to ensure all
fittings remain leak-tight. The Method 21 test would be supplemented by
annual visual inspections for leaking components as well as periodic
inspection and measurement of other monitoring parameters.
Special inspection and monitoring provisions are included in the
proposed standards for cover fittings that monitor. Leak monitoring
using Method 21 is not required for the following: (1) Drums that meet
applicable DOT regulations specified in the rules; (2) trucks,
trailers, and rail cars that are annually demonstrated to be vapor
tight by Method 27 in appendix A of 40 CFR part 60; and (3) closed-vent
systems operated under vacuum conditions.
K. Reporting and Recordkeeping
The proposed standards require the owner or operator to record
certain information in the on-site facility operating logs or files.
The information to be collected and recorded includes: the results of
all waste determinations such as volatile organic concentration at the
point of waste generation and organic vapor pressure; design
specifications for closed-vent systems and control devices and control
equipment; emission control equipment inspection and monitoring
results; Method 21 and Method 27 test results; control device
monitoring results; leak repairs; identification of incinerators,
boilers, or industrial furnaces in which wastewater is treated in
accordance with the general requirements of the rule; documentation for
biological wastewater treatment units complying with the rule; and
identification of equipment designated as unsafe or difficult to
monitor or inspect. This information is to be readily available for
review by authorized representatives of the EPA. The EPA seeks comment
on the accessibility of the monitoring data and periodic reports that
may be kept in logs on the plant site when it is not required to be
reported to the appropriate agency. These data and reports should be
accessible to citizen groups that contemplate citizen suits or other
members of the public interested in the source's compliance status.
This access is required by section 114(c) of the Clean Air Act as
Amended (CAAA). Means of providing that accessibility include: direct
inspection of the logs or files on-site with authority to access the
data equal to that of the EPA, submission of a Freedom of Information
Act (FOIA) request to the EPA with an affirmative duty on the part of
the EPA or the state/local delegated agent to obtain any data from the
source that the agency does not have in its files, submission of a
FOIA-like request to the source owner/operator with an obligation on
the part of the owner/operator to provide the requested data, or a
requirement to keep electronic files/logs which would be accessible
through EPA electronic bulletin boards. Other suggestions for meeting
the mandates of section 114 are welcome.
The General Provisions of 40 CFR part 60 require the owner or
operator to submit certain notifications and reports to the
Administrator. Section 60.7(a)(1) of the General Provisions requires a
notification of the date construction or reconstruction of an affected
facility is commenced; the proposed rule requires that certain general
information regarding the wastewater generated by the source be
submitted with this notification. Section 60.7(a)(3) of the General
Provisions requires a notification of the actual date of initial
startup of an affected facility; the proposed rule requires that the
owner or operator provide with this notification more detailed
information and data on the wastewater streams generated by the
affected process unit. This information includes a determination of
whether the stream is an affected wastewater stream, the compliance
approach utilized if the stream is being controlled in accordance with
the requirements of Sec. 60.109(b) of the proposed rule, the
identification of the waste management units receiving or managing each
affected wastewater stream, and certain information on the treatment
processes and control devices used to comply with the rule.
Section 60.7(c) of the General Provisions requires that each owner
or operator required to install a continuous monitoring system (CMS) or
monitoring device submit an excess emissions and monitoring systems
performance report and/or a summary report to the Administrator on a
quarterly basis when the CMS data are to be used directly for
compliance determination, as is the case for control devices in this
proposed rule. In order to be consistent with the reporting
requirements of the HON, which also regulates this industry, the EPA is
exempting the owner or operator from the quarterly reporting
requirement and is requiring only a semiannual report in the proposed
rule. The semiannual report will contain information on the excursions
or exceedances as determined by the CMS data, performance test results,
and other information on treatment processes and control devices.
III. Impacts of the Proposed NSPS
To estimate the impacts of the proposed regulation, the EPA
estimates the quantity of VOC that the affected industry would emit to
the atmosphere in the absence of the rule. This estimated quantity
serves as a baseline from which the impacts of the rule are measured.
Following estimation of the baseline level of emissions, the Agency
estimates the emission reduction that would occur as a result of the
regulatory alternatives for the rule. Studies are then made to estimate
the impacts of the rule on the environment, the economics of the
industry and the nation, and on energy consumption. Collectively, these
estimates represent the impacts of the standard. Estimated impacts
include emission reductions, costs, impacts on non-air environmental
media, and energy usage. The impacts presented here are those estimated
to occur in the fifth year after promulgation.
All of the impacts are calculated as an increment relative to the
impacts of the wastewater rules included in the HON. Additional details
of the impacts analysis can be found in the BID and from documentation
developed in support of the HON.
A. Environmental Impacts
Under the proposed NSPS, it is estimated that 68 percent of all new
SOCMI chemical production process units would have wastewater streams
that require control under the NSPS but do not require control under
the HON. It is further estimated that the total annual emission
reduction achieved by the NSPS in the fifth year would be approximately
16,200 megagrams per year (Mg/yr) of VOC. Because the NSPS requires the
treatment of wastewater prior to discharge, there would be no negative
impacts on water quality. In fact, the impacts of the rule on water
quality could be positive. Impacts of the rule on solid waste are
estimated to be negligible.
Other environmental impacts of the rule are estimated to be small.
Due to the increased energy requirements of control, emissions of
carbon monoxide are estimated to increase by about 4 Mg/yr and
emissions of nitrogen oxides are estimated to increase by about 35 Mg/
yr. Energy impacts of the proposed rule include the combustion of
fossil fuels to generate steam for steam stripping systems. These
impacts are partially offset by the recovery of organics from the
treatment system. Estimated energy impacts of the proposed rule in the
fifth year consist of an increase of 0.6 million kilowatt hours per
year (Kw-hr/yr) of electricity usage, an increase in natural gas
consumption of 133 million British thermal units per year (Btu/yr), and
an increase in steam usage of 133 billion Btu/yr.
B. Cost Impacts
The fifth-year cost impacts of the proposed standard are considered
to be reasonable. Total annualized cost of the rule in the fifth year,
on a nationwide basis, is estimated at $8.8 million. This results in a
cost effectiveness of about $540 per Mg of emission reduction. The
fifth-year national capital cost is estimated at approximately $5.8
million. The estimated cost impacts assume that most of the regulated
SOCMI plants with affected process units have an existing steam
stripping system with sufficient excess capacity to treat the
wastewater streams regulated under the NSPS or will be able to modify
steam stripping systems that are currently being designed and
constructed for compliance with other regulations (e.g., the HON) to
add sufficient capacity to treat the wastewater streams covered by the
proposed NSPS that do not require control under these other
regulations. The estimate also assumes that a small number (about 12
percent) do not have an existing steam stripper and will have to
install a new system. These assumptions reflect the Agency's best
estimate of the way the industry will comply with the rule.
C. Economic Impacts
The proposed rule is not expected to pose significant adverse
economic impacts. The impact estimates are also produced assuming the
costs of control are passed on to the consumer, as is the case in
competitive markets in the long run. The EPA estimates, on average, a
maximum price increase of less than 1 percent for SOCMI chemicals. This
assumes the entire mix of chemicals produced by an affected SOCMI
facility are proportionately affected by the NSPS, and assumes that the
chemicals produced at those SOCMI facilities in the EPA database are
reasonably representative of the mix of chemicals in the industry. The
market price impacts of specific chemicals may be greater than the
average presented above. This may be especially true for affected
chemicals produced in low volumes and affected chemicals that have
lower-than-average market prices. Chemicals with lower-than-average
prices could experience higher-than-average control costs per unit of
revenue. Due to economies of scale in pollution control, affected
chemicals that are produced in low volumes are likely to have a higher-
than-average cost of control per unit of production. The feature of the
proposed rule that exempts low volume wastewater streams from selected
process units may mitigate the price impact of low production volume
chemicals that produce low volume waste streams. Finally, there will be
no adverse effects on industry employment or expansion because the
proposed standards will not appreciably affect the demand for chemicals
covered by these standards.
IV. Rationale for Proposed Standards
A. Selection of Source Category
Under section 111(b)(1)(A) of the Act, the Administrator is
required to publish, and periodically update, a list of source
categories that in his or her judgement cause, or contribute
significantly to, air pollution which may reasonably be anticipated to
endanger public health or welfare. This list appears in 40 CFR 60.16
and ranks, in order of priority for standards development, various
source categories in terms of quantities of nationwide pollutant
emission, the mobility and competitive nature of each source category,
and the extent to which each pollutant endangers public health and
welfare. The priority list reflects the Administrator's determination
that emissions from the listed source categories contribute
significantly to air pollution that may reasonably be anticipated to
endanger public health or welfare, and it is intended to identify major
source categories for which standards of performance are to be
promulgated.
The priority list ranks the SOCMI source category first out of 59
listed source categories. For regulatory purposes, the SOCMI category
was divided into the following segments: SOCMI unit processes; volatile
organic liquid (VOL) storage vessels and handling equipment; SOCMI
fugitive sources; and SOCMI wastewater sources. Standards have been
developed for the other three groups of SOCMI sources; the NSPS
proposes standards for the fourth and final category of SOCMI sources.
This division of the source category on the basis of similar types
of emission sources and applicable emission control techniques was
chosen over a more traditional approach for NSPS that involves the
development of standards applicable to each specific chemical process.
The selected approach is more resource efficient than the chemical
process approach because a large number of specific chemical processes
can be covered by one regulation. In addition, SOCMI plants contain
similar wastewater emission sources. Similarities in the behavior of
wastewater emission sources in SOCMI allow the same control techniques
to be applied to all of the processes. Therefore, because the control
techniques can be applied to the entire industry group and because
regulating the entire group would be more resource efficient, a single
regulation is being proposed for controlling wastewater emissions from
the SOCMI source category.
The SOCMI is a large and diverse industry producing several
thousand intermediate and end-product chemicals from a small number of
basic chemicals. Most of the chemicals produced by this industry fall
under standard industrial classification code 286.
In the proposed rule, a SOCMI process unit is defined as one
producing or using one or more of the chemicals listed in the
regulation. The list of chemicals proposed is an inclusive list that
was derived from several sources that also formed the basis for the
initial list of chemicals used to characterize SOCMI process units in
the HON (see appendix A of the HON BID, EPA-453/D-92-016). The
following sources are the basis for the composite list of chemicals for
the proposed NSPS: (1) ``Industrial Organic Chemical Use Trees,'' EPA/
ORD, October 1992; (2) Standards of Performance for Equipment Leaks of
VOC in SOCMI, 40 CFR part 60, subpart VV; (3) Proposed Standards of
Performance for SOCMI Reactor Processes, 55 FR 26953, June 29, 1990;
(4) Standards of Performance for SOCMI Distillation Operations, 40 CFR
part 60, subpart NNN; and (5) Standards of Performance for SOCMI Air
Oxidation Processes, 40 CFR part 60, subpart III. Therefore, the
proposed list is a compilation of all the chemicals in these databases
used to characterize the SOCMI process units.
B. Selection of Emission Sources
There are several emission sources associated with SOCMI processes
(e.g., process vents, product storage and transfer operations, and
equipment leaks); however, this NSPS is directed toward the control of
VOC emissions from wastewater generated by SOCMI process units. This
includes emissions from wastewater collection and treatment operations.
Wastewater streams that contain organic compounds are generated at
SOCMI process units by one of two mechanisms, either direct contact of
water with organic compounds or by contamination of indirect contact
water through equipment leaks in chemical processing.
Water may come in direct contact with organic compounds during a
variety of different chemical processing steps, thus generating
wastewater streams (referred to as ``process wastewater'') that must be
discharged for treatment or disposal. Direct contact wastewater
includes water used to wash impurities from organic compound products
or reactants, water used to cool or quench organic compound vapor
streams, condensed steam from jet educator systems pulling vacuum on
vessels containing organic compounds, water from raw material and
product storage tanks, water used as a carrier for catalysts and
neutralizing agents (e.g., caustic solutions), and water formed as a
byproduct during chemical reactions. Direct contact wastewater is also
generated within SOCMI process units when water is used in equipment
washes and spill cleanups; this wastewater (referred to as
``maintenance wastewater'') is typically more variable in flow rate and
concentration than process wastewater streams and may be collected in
ways that differ from process wastewater.
Indirect contact wastewater streams are generated by unintentional
contact with organic compounds through leaks in process equipment. For
example, indirect contact wastewater may be generated as a result of
leaks from heat exchangers, condensers, or pumps. These wastewaters
also may be collected and treated differently from direct contact
wastewaters.
In both the SOCMI NSPS and the HON, ``wastewater'' is defined to
encompass both process wastewaters and maintenance wastewaters.
Examples of process wastewater streams include, but are not limited to,
wastewater streams exiting process unit equipment (e.g., decanter
water, such as condensed steam used in the process), product tank
drawdown, feed tank drawdown, filter-press filtrate, and residuals
recovered from waste management units. Examples of maintenance
wastewater streams, which encompass all maintenance-related wastewater
streams, are those generated by descaling of heat exchanger tubing
bundles, cleaning of distillation traps, and draining of pumps into an
individual drain system. However, the regulatory approach taken in the
SOCMI NSPS is different from the one taken in the final HON. The
proposed SOCMI wastewater NSPS requires that controls be applied to
reduce air emissions from both process and maintenance wastewater
streams from SOCMI process units that produce any of the listed
chemicals. In the HON, maintenance wastewater is regulated by subpart
F, and process wastewater is regulated by subpart G. Subpart F,
Sec. 63.105, requires the source owner or operator to develop a
startup, shutdown, and malfunction plan which includes a description of
procedures for managing wastewaters generated during maintenance. In
the final HON, the facility's plan must include a description of
procedures that will ensure that all maintenance wastewater is properly
managed and HAP emissions are controlled. No such plan is required in
the proposed NSPS.
The EPA selected the regulatory approach for maintenance wastewater
as proposed in the NSPS because it was determined through review of the
industry, which included plant visits to newly constructed SOCMI
process units, that the technologies available for the collection and
treatment of these wastewaters have been adequately demonstrated at
SOCMI plants. The EPA is soliciting comments on the proposed approach
to regulating SOCMI process unit maintenance wastewaters. The EPA is
interested in receiving information on why new SOCMI process units
could not be designed and operated to control air emissions from
maintenance wastewaters in the same manner as process wastewaters and
information on the impact the small-quantity cutoff for process units
and the low-flow exemption for wastewater streams will have on the
collection and treatment of SOCMI maintenance wastewaters in relation
to air emission control.
Wastewater streams at SOCMI plants are collected and treated in a
variety of ways. Generally, wastewater passes through a series of
collection and treatment units before being recycled to the facility or
discharged from the facility. Collection and treatment schemes for
wastewater are facility specific. The flow rate and organic compound
composition of wastewater streams at a particular plant are functions
of the processes used, which in turn influence the sizes and types of
collection and treatment units. Many of the collection and treatment
system units are either directly or indirectly open to the atmosphere;
this atmospheric interface creates a potential for VOC emissions. The
magnitude of VOC emissions from SOCMI process unit wastewaters is
dependent on factors such as the physical properties of the pollutants,
the temperature of the wastewater, and the design of the individual
collection and treatment unit managing the wastewater. Climatic factors
such as ambient temperature and wind speed also affect VOC emissions at
many wastewater collection and treatment units. Potential sources of
VOC emissions associated with wastewater collection and treatment
systems include individual drain systems, manholes, junction boxes,
lift stations, trenches, sumps, weirs, oil-water separators,
equalization or neutralization basins, clarifiers, aeration basins,
storage and treatment tanks, surface impoundments, and containers. A
discussion of each of these emission sources is contained in Chapter 3
of the BID.
C. Pollutants to be Regulated
New source performance standards are developed under the authority
of section 111 of the Act. Section 111 of the Act requires the
regulation of new and modified sources of criteria pollutants
(identified under section 110 of the Act) and certain other designated
pollutants.
Volatile organic compounds are regulated due to their contribution
to the formation of ozone in the lower atmosphere. Ozone is a listed
criteria pollutant. Exposure to ozone has been linked to both health
and welfare impacts. Health and welfare risks from these include
impaired respiratory function, eye irritation, deterioration of
materials such as rubber, and necrosis of plant tissue.
The potential for VOC emissions from wastewater can be assessed
based on the characteristics of the wastewater at its point of
generation. Based on information and data gathered on the concentration
of organics in SOCMI wastewater streams and on the flow rate of these
streams, the VOC emissions from SOCMI wastewater streams are considered
to cause or contribute significantly to air pollution.
D. Selection of Affected Facility
The choice of the affected facility for an NSPS is based on the
Agency's interpretation of section 111 of the Act. Under section 111,
the NSPS must apply to ``new sources''; ``source'' is defined as any
building, structure, facility, or installation which emits or may emit
``any air pollutant.'' Most industrial plants, however, consist of
numerous pieces or groups of equipment which emit air pollutants, and
which might be viewed as ``sources.'' The EPA uses the term ``affected
facility'' to designate the equipment, within a particular kind of
plant, which is chosen as the ``source'' covered by a given standard.
In choosing the affected facility, the EPA must decide which pieces
or groups of equipment are the appropriate units for separate emission
standards in the particular industrial context involved and in light of
the terms and purpose of section 111. One major consideration in this
examination is that the use of a broader definition means that
replacement equipment is less likely to be regulated under the NSPS;
if, for example, an entire plant were designated as the affected
facility, no part of the plant would be covered by the standard unless
the plant as a whole were ``modified.'' Because the purpose of section
111 is to minimize emissions by the application of the best
demonstrated control technology (considering cost, other health and
environmental effects, and energy requirements) at all new and modified
sources, there is a presumption that a narrower designation of the
affected facility is appropriate. This ensures that new emission
sources within plants will be brought under the coverage of the
standards as they are installed. This presumption can be overcome,
however, if the Agency concludes that the relevant statutory factors
(technical feasibility, cost, energy, and other environmental impacts)
point to a broader definition. Another factor considered in the
selection of an affected facility for the NSPS is the definition used
in existing environmental rules. The application of these factors is
discussed below.
The SOCMI is normally represented as a system of production stages
that produce a wide range of organic chemicals from a set of 11 basic
chemicals. The basic set of 11 chemicals is generated by refineries,
natural gas plants, and coal tar distillation plants. Organic chemicals
are produced at a wide range of facilities, from large facilities
manufacturing a few chemicals in large volumes, to smaller facilities
manufacturing many different finished chemicals in smaller volumes.
Each of the production stages or ``process units'' may include any of
several VOC emission sources, one of which is collection and treatment
of wastewater.
Three alternatives were considered for defining the affected
facility in the NSPS. One option considered was to use a variation of
the definition of source used in the HON, which is ``* * * the set of
emission points in the organic HAP-emitting processes used to produce
synthetic organic chemicals that are in a contiguous area under common
control.'' Under this option of broadly defining the source for the
NSPS, the affected facility would include all process units and
associated process unit wastewater streams located at a plant with
SOCMI process units. A second option considered was the narrow
definition used in the NSPS for refinery wastewater (40 CFR part 60,
subpart QQQ), which was ``(1) individual drain systems, (2) oil-water
separators, and (3) aggregate facilities, which are defined as all
process drains connected to the first common downstream junction box
down to the receiving oil-water separator.'' The third and final option
considered was ``each individual SOCMI process unit'' where each SOCMI
process unit is defined as the equipment assembled and connected by
pipes or ducts that use or produce, as intermediates or final products,
one or more of the chemicals listed in the NSPS applicability section.
(A process unit can be operated independently if supplied with
sufficient feed or raw materials and sufficient product storage
facilities.)
The broader first option has been used previously by the EPA in an
existing NESHAP (i.e., the HON) as the source definition for existing
SOCMI facilities. (Note: Under the HON's new source provisions, new
SOCMI process units are subject to the rule requirements under a more
narrow source definition when specified conditions are met.) In that
regulation, the definition was purposely chosen to be broad to include
all emission points at any given site under the regulation. As stated
earlier, a broad definition under an NSPS has a different effect. If an
entire site is designated as the affected facility for an NSPS,
existing sources only become subject to the NSPS if the entire site is
modified or reconstructed.
Under the second option, each piece of equipment in the wastewater
collection and treatment system would be considered a unique or
individual affected facility. This definition, which has a precedent in
the refinery wastewater NSPS, is much narrower and more restrictive
than the first option. In general, the narrower the definition of
source, the more likely it is that changes to existing facilities will
be deemed ``new sources'' under the Act. This definition would result
in numerous sources within each SOCMI process unit, as well as numerous
sources within the wastewater collection and treatment system, being
classified as affected facilities.
The third option, that of considering each process unit as an
affected facility, also has recent precedent. The standards for process
wastewater components of the proposed pulp and paper rule (58 FR 66077,
December 17, 1993) are structured such that the process unit is the
affected facility, and controls are required for wastewater streams
generated by these units. This approach is also consistent with the one
taken in the HON for regulation of new SOCMI process units. Defining
the affected facility on a process unit basis avoids the problems
associated with having multiple individual collection and treatment
system equipment components classified as affected facilities, and it
also provides a definition sufficiently narrow in scope so as not to
preclude the possibility that existing sources will become subject to
the NSPS through the modification and reconstruction provisions. Most
importantly, defining an affected facility as a process unit reflects
industry construction practices. Almost all new construction,
reconstruction, and modification in the SOCMI is carried out by process
unit.
After carefully considering each of the above alternatives, the EPA
selected process units as the basis for defining affected facilities
for the proposed NSPS. This definition allows for routine equipment
replacement and minor changes or expansions in existing facilities
without subjecting either single emission sources or entire plant sites
to requirements of the proposed standards. Providing for full coverage
of all new process units will improve ambient air quality, the goal of
standards implemented under section 111.
Synthetic organic chemical manufacturing industry process units,
which are defined as the equipment assembled and connected by pipes or
ducts to process raw materials and to manufacture an intended product,
include reactors and their associated product separators and recovery
devices; distillation units and their associated distillate receivers
and recovery devices; associated unit operations; and any feed,
intermediate, and product storage vessels, product transfer racks, and
connected ducts and piping. A synthetic organic chemical manufacturing
process unit includes pumps, compressors, agitators, pressure relief
devices, sampling connection systems, open-ended valves or lines,
valves, connectors, instrumentation systems, and control devices or
systems.
E. Selection of Best Demonstrated Technology
Section 111 of the Act states that NSPS ``shall reflect the degree
of emission limitation and the percentage reduction achievable through
application of the best technological system of continuous emission
reduction which (taking into consideration the cost of achieving such
emission reduction, any nonair quality health and environmental impact
and energy requirements) the Administrator determines has been
adequately demonstrated.'' The technological basis for NSPS that meets
these criteria is referred to as ``best demonstrated technology
(BDT).'' In the standards development process for NSPS, BDT should be
identified, the performance of BDT established, and a regulatory
alternative selected that will require the use of BDT or an equivalent
technology.
There are two fundamentally different approaches to controlling VOC
emissions from SOCMI wastewater sources. The first is a source
reduction or waste minimization approach in which the emission
reduction is achieved through a reduction in the quantity of wastewater
generated and/or a reduction in the VOC content of the wastewater as a
result of process modifications, modifications of operating practices,
improved preventive maintenance activities, increased recycling, or
segregation of VOC-containing waste streams.
Waste minimization may be achieved through either source reduction
or recycling. Source reduction involves the implementation of steps
that reduce either the amount of wastewater generated or the amount of
VOC contained in the wastewater streams. Recycling includes recovery
and/or reuse of potential wastes. Within the SOCMI, there are several
means of achieving the objective of either of these waste minimization
alternatives. However, in relation to SOCMI wastewater, waste
minimization techniques are, for the most part, process unit-specific,
and the degree of emission reduction achieved depends on the operating
parameters of the individual process unit.
Because of a lack of adequate site-specific data regarding the
waste minimization approach within SOCMI, the EPA was unable to develop
reasonable estimates of the emission control efficiency of the waste
minimization options achievable on a nationwide basis. For example,
because pollution prevention activities such as process redesign are
site-specific, it would not be practical or possible to stipulate
specific requirements for the large number of chemical production
processes subject to the proposed SOCMI wastewater NSPS. In addition,
the EPA considers that elimination of pollution through material
substitution will not be possible in all cases within the SOCMI because
SOCMI products cannot be eliminated from use without adverse economic
impact. Specifically, because the products of the SOCMI are used in the
production of polymers, resins, pesticides, pharmaceuticals, etc.,
elimination of a SOCMI product would affect not only the SOCMI producer
but also the downstream user of that SOCMI product. Many of the end-use
products (e.g., resins, pharmaceuticals, etc.) could not be made from
other materials. Thus, the EPA maintains that material substitution is
better left determined by the marketplace than by mandate through a
specific Federal requirement. Therefore, for the reasons cited above,
no waste minimization options were included in the regulatory
alternatives analysis for this NSPS.
The EPA, however, believes that the SOCMI wastewater NSPS
sufficiently encourages pollution prevention. For example, within the
regulation's applicability provisions, there is an exemption from the
control requirements of the rule for process units that generate
wastewaters with small overall volatile organic quantities in the
wastewater. Also, the regulatory criteria for identifying the
wastewater streams that require control for air emissions are expressed
in terms of action levels based on concentration and flow rate cutoffs
below which controls are not required for the wastewater stream. An
owner or operator may use any means, including process changes or
material substitution but not treatment of the wastewater, to meet the
criteria for either the small quantity process unit exemption or the
concentration/low-flow cutoff. In addition, within the provisions for
wastewater collection and treatment operations, there are compliance
options that only specify a percent reduction of VOC emissions. Again,
to comply with these options, an owner or operator may use any means,
including process changes or recovery devices, to reduce emissions by
the specified percent.
The second approach to achieving emission reductions involves
emission suppression and treatment of wastewater streams to remove or
destroy the organic compounds. Volatile organic compound emissions from
SOCMI process unit wastewater can be effectively reduced on a
nationwide basis with the following control approach: (1) Identify
wastewater streams with significant VOC emission potential; (2) recycle
or treat those wastewater streams to remove their potential for
emissions; (3) prior to treatment or recycling, manage those waste
streams in units that suppress emissions or are equipped with air
emission controls; (4) recycle any treatment residuals or treat any
residuals to destroy VOC; and (5) control air emissions generated by
the treatment processes.
The potential for VOC emissions from wastewater can be assessed
based on the characteristics of the wastewater at its point of
generation. A reference test method, EPA Method 25D (40 CFR Part 60,
appendix A), provides a relative indicator of wastewater emission
potential and is used as a tool to implement air emission standards for
wastewater. This method, when applied to a wastewater stream, yields a
volatile organic concentration for the stream. While not a true
indicator of absolute emissions, the volatile organic content of a
stream provides a relative indicator of the potential emissions of that
stream as compared to other streams that are similarly managed.
There are three primary treatment technologies that are generally
applicable and effective in reducing the VOC content of SOCMI
wastewater streams. These are steam stripping, air stripping, and
biological treatment. There also are several other technologies or
methods of treatment that are equally effective in their particular
situations but are limited in their applicability within SOCMI. These
other technologies include chemical oxidation, carbon and ion exchange
adsorption, membrane separation, and liquid-liquid extraction.
Steam stripping is the most universally applicable VOC removal
technology for treating wastewater streams generated by SOCMI process
units, and this treatment technology has been selected as the basis for
standards for SOCMI wastewater. The VOC removal efficiency of steam
strippers depends on the characteristics of both the steam stripper and
the wastewater stream. Data collected by the EPA related to steam
stripper performance for the treatment of wastewaters indicate that
organic removal efficiencies of up to 99.9 percent have been
demonstrated on wastewater streams at SOCMI plants.
The EPA selected steam stripping as the BDT because it is the most
universally applicable treatment technology for removing organic
compounds from wastewater streams with the potential to emit VOC and
achieves the highest VOC emission reduction among demonstrated VOC
control technologies. The EPA is aware that many SOCMI facilities
employ biological treatment units for wastewater treatment. However,
not all of the compounds regulated under the proposed NSPS are
significantly biodegradable, while most of the compounds can be treated
more readily by steam stripping. In addition, the amount of emissions
reduction achieved by biological treatment, even for biologically
degradable compounds, will vary among SOCMI sources because of the
ranges in operating and design parameters, such as the biological
degradation rate, surface area of the unit, aeration rate, hydraulic
residence time, and the active biomass concentration. When reviewing
biological treatment as the potential BDT, the EPA determined that the
variability in performance is significant across the industry. Although
a well operated and maintained biological treatment system can achieve
reductions as high as 99 percent, the variability in performance makes
quantifying emission reductions for the purpose of setting a standard
more difficult than for steam stripping. Emission reductions for
biological treatment systems can only be determined on a site-specific
basis. However, the EPA emphasizes that SOCMI sources using biological
treatment, or any other treatment technologies, can comply with the
rule by consistently achieving the required emission reduction (i.e.,
95 percent when using biodegradation or 99 percent for other
technologies).
To achieve the desired emission reduction from steam stripping or
other treatment technology, it is necessary to suppress the wastewater
emissions from the point of generation to the treatment device where
the organic compounds are either removed or destroyed. Suppression of
emissions can be achieved by using physical covers, roofs, and water
seals to minimize the contact between the wastewater and the
atmosphere. Examples of controls for air emissions from waste
management units in a wastewater collection and treatment system, based
on suppression techniques, include: fixed or floating roofs on tanks,
water seals on drains, gas-tight covers on junction boxes, and covers
and enclosures around oil-water separators. Hard piping of a wastewater
stream from its point of generation to the steam stripper unit is one
method to achieve the suppression of air emission from the wastewater.
However, wastewater streams may be managed in other units prior to
treatment if those units are equipped with air emission controls.
F. Selection of Format of Proposed Standard
Section 111 of the Act requires an emission standard whenever it is
feasible. Section 111(h) states that ``if in the judgment of the
Administrator, it is not feasible to prescribe or enforce a standard of
performance, he may instead promulgate a design, equipment, work
practice, or operational standard, or combination thereof * * * '' The
term ``not feasible'' is applicable if the emissions cannot be captured
and vented through a vent or stack designed for that purpose, or if the
application of a measurement methodology is not practicable because of
technological or economic limitations. The EPA is proposing standards
for VOC emissions from the process unit wastewater segment of this
source category. To ensure that emissions are captured and conveyed to
a control device, the proposed standards include requirements for:
(1) An enclosed wastewater collection and treatment system;
(2) Treatment to reduce VOC concentration in the wastewater
streams; and
(3) Conveyance of emissions vented from the wastewater treatment
device and the enclosed wastewater collection system in a closed-vent
system to a control device.
Applicability levels are included in the SOCMI wastewater standards to
identify those process unit wastewater streams that are required to be
controlled. Alternative formats were considered for applicability
levels, waste management units, wastewater treatment processes, and
vent collection and vapor recovery or destruction devices.
1. Applicability Levels
The EPA identified certain low flow and low concentration
wastewater streams that are not believed to be controlled at existing
facilities. Parameters that characterize these streams include volatile
organic concentration of the stream and volumetric flow rate, both of
which can be determined by using a variety of methods. Therefore, the
EPA is proposing concentration and flow rate parameters to identify
process unit wastewater streams that do not require control. The EPA
also is proposing that process units that generate wastewater with a
total annual mass of volatile organics less than 1 Mg per year are
exempt from the control requirements of the rule. The EPA solicits
comment on whether it is feasible to otherwise identify specific
process unit wastewater streams to be controlled. The EPA also solicits
information on defining these process unit wastewater streams.
2. Waste Management Units
Two formats were considered in developing the proposed standards
for waste management units. These formats were a numerical emission
standard and an equipment and work practice standard. A numerical
standard would not be feasible because it would be difficult to capture
and measure emissions from SOCMI waste management units (i.e., tanks,
surface impoundments, containers, individual drain systems, and oil-
water separators) for the purpose of evaluating compliance. Due to the
number of openings and possible emissions points, accurate measurement
would require enclosure of the entire airspace around each piece of
equipment. This approach would not be practical for numerous equipment
components. Therefore, the Administrator concluded that the format of
the standards for this source category should include a combination of
a design, equipment, work practice, and operational standards.
In the case of SOCMI waste management units, the intent of the
standard is to suppress and capture emissions from the process unit
wastewater collection and treatment equipment. The suppression and
capture of emissions is accomplished by the installation and proper
maintenance of roofs, covers, lids, water seals, and enclosures on
tanks, surface impoundments, containers, individual drain systems, and
oil-water separators. Captured emissions are then vented to a control
device through application of a closed vent system. Work practices such
as periodic monitoring, inspection, and repair, would be required to
ensure proper operation and maintenance of the equipment.
The proposed standards would require that emissions from waste
management units be controlled from the point of generation until the
wastewater stream leaves the treatment device or is recycled to the
process.
3. Wastewater Treatment Processes
Three formats were considered in developing the proposed standards
for reduction of process unit wastewater stream VOC concentration: a
numerical format (i.e., emission standard), an equipment design and
operational format, and an equipment and work practice standard.
a. Emission Limitation. Three alternative numerical emission
limitation formats are proposed to provide sources with a maximum
degree of operational flexibility in complying with the standards.
These emission limitation formats are: a mass percent reduction of VOC
in the process unit wastewater stream, an effluent concentration
limitation for VOC for individual wastewater streams, or a mass removal
requirement for combined wastewater streams. The rationale for
providing these alternative emission limitations is discussed below.
The percent reduction format is based on the VOC removal efficiency
of a steam stripper; however, any treatment process that can achieve
the proposed efficiency can be used to comply with the standard. (See
section IV.G for more discussion.) Percent reduction was chosen because
it is the best representation of control technology performance, and it
may be applied to any configuration of wastewater streams.
The effluent concentration limitations are also based on the
performance of a steam stripper. Effluent concentration limitations are
provided as alternatives to the percent reduction standard to allow
compliance flexibility for facilities required to treat process unit
wastewater streams. The use of this alternative is limited to
facilities that are treating only affected wastewater streams. The
effluent concentration limit is not applicable to situations where
combinations or mixtures of both affected and unaffected wastewater
streams are treated.
Dilution becomes a concern when more than one waste stream is sent
to a single treatment process. For example, diluting a waste with other
materials having a volatile organic concentration less than 500 ppmw as
a means by which an owner or operator lowers the volatile organic
concentration of the waste from an affected stream to a level below 500
ppmw would not comply with the requirements of the proposed standards.
A process that simply mixes, blends, combines, or aggregates a waste
with other materials does not destroy the VOC in the waste or remove
the VOC from the waste. Consequently, when a waste is treated by an
organic destruction or removal process, and the waste has been mixed or
aggregated together with other wastes or materials with a volatile
organic concentration less than 500 ppmw prior to the point of waste
treatment, the proposed standards would require that owners or
operators meet special requirements to ensure that organics in the
waste have actually been removed or destroyed. Under the proposed
rules, an owner or operator would be allowed to use a mass reduction
requirement to meet the standards.
Required mass removal is an alternative for combined wastewater
streams. This provision would require that mixed wastes be treated by
an organic destruction or removal process that reduces the volatile
organic concentration of the waste to meet a site-specific treatment
process mass removal limit. This limit would be determined by the owner
or operator on a case-by-case basis using an equation specified in the
rules that accounts for the reduction in the volatile organic
concentration of the resulting treated waste stream due to dilution. To
use this equation, the owner or operator would first determine the
volatile organic concentration at the point of waste entry for each
individual waste stream that is mixed together prior to entering the
treatment process.
b. Equipment Design and Operation Format. Another regulatory format
proposed for process unit wastewater stream treatment is an equipment
design and operational format. The equipment standard consists of the
installation of a steam stripper designed and operated at specified
parametric levels. The specifications for the steam stripper were
developed to provide a standard piece of equipment (with associated
operating conditions) that can achieve either the mass percent VOC
removal or the effluent concentration of VOC.
This equipment design and operational format was included to
provide an alternative means of compliance that all sources would be
able to use, while achieving the desired emission reduction.
c. Equipment and Work Practice Format. A final equivalent standard
proposed for controlling process unit wastewater emissions is an
equipment and work practice standard. This format is based on the
recycling of process unit wastewater in a closed collection system to
the process. When recycling is used, process unit wastewater emissions
are controlled with equipment emissions, and the process unit
wastewater is reused. This format is proposed to encourage chemical
recovery and waste minimization and pollution prevention.
4. Vent Collection and Vapor Recovery or Destruction Devices
An emission standard and two equipment and design standards are
proposed for VOC that are routed to vapor recovery or destruction
devices used to control VOC from vent collection sources. The proposed
emission standard includes two alternatives: a weight percent reduction
and an outlet concentration. A mass emission limit was not appropriate
for these emission points because variation within the industry,
including capacity and processes, greatly affects emission rates, and
data were not available to determine the mass limits that would address
this variation. In general, a weight percent reduction format will
ensure that BDT is applied and the required emission reductions are
realized. However, combustion technology that is equivalent to BDT
cannot be demonstrated to achieve the selected percent reduction for
streams with low VOC concentrations. Therefore, an alternative
concentration limit that is achievable has been included. The
combination of the weight percent reduction or concentration limit will
ensure that the best technology is applied to all SOCMI process
emission points, whether they have higher or lower concentrations.
Two equivalent standards, each of which is an equipment and design
standard, are also proposed. The first equipment and design standard is
the requirement that gas streams be routed to a combustion device
(other than flares) designed and operated at a minimum temperature and
residence time. For flares, an equipment standard with stated equipment
and operating specifications is being proposed as the format because it
is very difficult to measure emissions from a flare to determine its
efficiency. These standards have been determined by the EPA to be
equivalent to the emission standards and are proposed to provide
maximum compliance flexibility.
G. Selection of Standards
This section discusses the rationale for the selection of the
standards for the SOCMI process unit wastewater source category. The
selection of applicability levels, numerical limitations for the
emission standards, and design parameters are included.
1. Applicability Levels
For the purposes of developing wastewater standards, the EPA has
concluded that the effectiveness of the control technologies available
to limit VOC emissions from wastewater does not vary. Controls are
assumed to be either ``on'' or ``off,'' depending on whether a
particular stream is identified as one that must be controlled.
Therefore, the basic foundation of the proposed provisions for SOCMI
process unit wastewater is to identify wastewater streams for control
and treatment based on a specific criteria or action level at the point
of wastewater generation, prior to dilution and air emissions losses.
Control of a wastewater stream is triggered if it is determined that
the stream exceeds the action level established by the standard. With
this approach, the primary decision that needs to be made in
establishing BDT is selecting the appropriate action level for the
source category.
Regulatory alternatives for a standard to control emissions from
wastewater have, in previous EPA regulatory analyses, been typically
expressed in terms of action levels based on a concentration cutoff
above which a wastewater stream must be controlled. For the SOCMI
wastewater NSPS, the primary action level will be defined in terms of
the volatile organic concentration, as measured by method 25D. The
standard also includes exemptions for low flow streams. This is in
consideration of the fact that, even though a waste stream may exceed
an action level, the total mass of contaminant present in a stream with
a low flow rate is low enough that the waste or wastewater stream does
not have the potential for significant emissions. Process units that
generate wastewater with a total annual volatile organic mass less than
1 Mg are also exempt from the control requirements of the proposed
rule. The impacts analysis indicated that the 1 Mg/yr small quantity
exemption has little effect on the emission reductions achieved under
the regulatory alternatives examined while significantly reducing the
overall cost of compliance.
The five regulatory alternatives analyzed in the development of the
proposed standard were combinations of volatile organic concentrations
and flow rate cutoffs. The alternatives were analyzed both with and
without the small quantity cutoff of 1 Mg per year of volatile organic
mass. For each regulatory alternative, steam stripping (or an
equivalent emission reduction technique) would be required for all
wastewater streams with flow rates and volatile organic concentrations
greater than their respective action levels.
Values were chosen for concentration and flow rate cutoffs to span
ranges believed by the EPA to be reasonable based on knowledge of the
SOCMI wastewater streams to be regulated and on previous standards
development efforts. Further, the ranges of flow rates and
concentrations represented in these alternatives, when impacts are
estimated, illustrate the range of cost-effectiveness levels that apply
to regulatory alternatives and allow selection of an alternative that
will achieve optimum control (i.e., greatest emission reduction for
lowest cost).
As previously noted, method 25D provides a relative indicator of
wastewater emission potential. While not a true measure of VOC
emissions, the volatile organic concentration of a wastewater stream
does provide a relative means of comparing the emission potential of a
wastewater stream to other streams similarly managed and of comparing
the emission potential of a wastewater stream before and after
treatment.
Because the proposed rule regulates VOC emissions, the first choice
for a test method is one that measures the concentration of all VOC.
However, this approach would require speciation test methods which are
costly to use. As an alternative, the EPA selected method 25D which
does not speciate but measures total volatile organic concentration.
This method, which is much less costly, has been used in other
wastewater related regulations. For example, method 25D is allowed in
the HON for measuring volatile organic concentration in applicability
determinations. However, the HON does not allow use of method 25D in
calculations of mass removal for treatment processes. Instead, the HON
uses a test method that speciates HAPs for determining mass removal by
treatment.
As currently structured, the proposed rule would make extensive use
of the volatile organic concentration (as measured by Method 25D). The
concentration cutoffs for determining if a wastewater stream is an
affected stream are formatted in terms of the volatile organic
concentration. The small quantity cutoff of 1 Mg/yr is calculated using
the volatile organic concentration; the effluent concentration limit is
expressed in term of volatile organic concentration; and the mass
removal requirements of the proposed rule are calculated using the
volatile organic concentration. The EPA is aware that using the
volatile organic concentration rather than a direct measure of VOC does
have some limitations and drawbacks. The test method used to measure
volatile organic concentration, Method 25D, is based on volatility
(i.e., Henry's Law) and does not speciate organic compounds. Therefore,
the results may reflect the presence of compounds that are not
considered VOC (based on their photochemical reactivity). The EPA is
considering ways of discounting the non-VOC components of the test
results but has not included a means to do so in the proposed
regulation. One option for accomplishing this would be to allow owners
or operators the option of using a test method that speciates VOC. If
this approach is selected, provisions could also be made to allow the
measured VOC concentration to be adjusted to represent VO concentration
by multiplying by the fraction emitted (fm) values reported in the
IWW CTG. The EPA also intends to include an alternative percent
reduction standard based on the stripability of specific volatile
organic constituents. This approach is also described in the IWW CTG.
Because of the issues associated with the use of method 25D for
applicability and compliance determinations, the EPA is soliciting
comments all aspects of this approach.
Regulatory Alternative 1 is to require emission control only of
those SOCMI process unit wastewater streams having a volatile organic
concentration at the point of wastewater generation equal to or greater
than 1,000 ppmw and a flow rate greater than or equal to 10 Lpm.
Regulatory Alternative 2 is to require emission control only of those
SOCMI process unit wastewater streams having a volatile organic
concentration at the point of wastewater generation equal to or greater
than 800 ppmw and a flow rate greater than or equal to 5 Lpm.
Regulatory Alternative 3 is to require emission control only of those
SOCMI process unit wastewater streams having a volatile organic
concentration at the point of wastewater generation equal to or greater
than 500 ppmw and a flow rate greater than or equal to 1 Lpm.
Regulatory Alternative 4 is to require emission control only of those
SOCMI process unit wastewater streams having a volatile organic
concentration at the point of wastewater generation equal to or greater
than 100 ppmw and a flow rate greater than or equal to 1 Lpm.
Regulatory Alternatives 1 through 4 also have a maximum volatile
organic concentration limit whereby any wastewater stream with a
volatile organic concentration above the limit would require emission
control regardless of the wastewater stream flow rate; for Regulatory
Alternatives 1 through 4, the same maximum concentration limit of
10,000 ppmw was used in the regulatory alternatives analysis.
Regulatory Alternative 5 is to require air emission control for all
SOCMI process unit wastewater streams with any detectable volatile
organic concentration as determined at the point of wastewater
generation (i.e., a volatile organic concentration action level of 0
ppmw).
The EPA estimated nationwide VOC emission reductions that would be
achieved by implementing air rules based on each of the five regulatory
alternatives; the EPA also estimated the capital and annual cost of
achieving the emission reductions and the nonair quality environmental
and energy impacts associated with each regulatory alternative. These
estimates of emissions and costs reflect the annual impacts in the
fifth year following promulgation of the NSPS. The methodology used to
develop estimates of VOC emissions and other impacts within the SOCMI
source category for the five regulatory alternatives is based on the
use of a model plant analysis and is discussed in detail in Chapter 6
of the BID and in docket number A-94-32.
Model plants are typically defined to represent the affected
facility over a range of sizes corresponding to the range found in the
regulated industry. Two previous EPA studies developed model plants
that relate to emissions from wastewater streams at SOCMI facilities:
the Guideline Series Document for the Control of Volatile Organic
Compound Emissions from Industrial Wastewater (EPA-453/D-93-056,
September 1992 Draft) and the BID related to the development of the HON
(EPA-453/D-92-016, November 1992). The EPA developed model plants for
the SOCMI wastewater NSPS regulatory analysis by making use of
information, data, and methodologies developed in these previous
studies.
In the absence of implementing any of the regulatory alternatives
(baseline), nationwide, fifth-year wastewater VOC emissions from new,
modified, and reconstructed SOCMI process units are estimated to be
approximately 37.2 thousand Mg/yr. Assuming implementation of the
individual regulatory alternatives, the emissions are 24.1 thousand Mg/
yr for Regulatory Alternative 1, an emission reduction from baseline of
13.0 thousand Mg/yr achieved at total annual cost of about $4.3
million; 23.1 thousand Mg/yr for Regulatory Alternative 2, an emission
reduction from baseline of 14.0 thousand Mg/yr achieved at total annual
cost of about $5.2 million; 21.0 thousand Mg/yr for Regulatory
Alternative 3, an emission reduction from baseline of 16.2 thousand Mg/
yr achieved at total annual cost of about $8.8 million; 18.6 thousand
Mg/yr for Regulatory Alternative 4, an emission reduction from baseline
of 18.6 thousand Mg/yr achieved at total annual cost of about $15.6
million; and 14.2 thousand Mg/yr for Regulatory Alternative 5, an
emission reduction from baseline of 22.9 thousand Mg/yr achieved at
total annual cost of about $41.1 million.
The control costs reflect the fact that most plants affected by the
NSPS will also be affected by the HON, and they are expected to install
a steam stripper for treating wastewater streams regulated by the HON.
The proposed NSPS will require these SOCMI plants to control additional
wastewater streams that do not require control under the HON. In
estimating cost impacts of the NSPS, the EPA assumed that those plants
affected by both regulations would increase the capacity of the steam
stripper required under the HON rule to provide sufficient capacity to
handle the additional wastewater streams that would require control
under the NSPS. The costs associated with the NSPS is the difference in
costs for the two steam strippers, one with the capacity to handle
wastewater streams regulated by the HON and the other with the capacity
to handle wastewater streams regulated by both the HON and the NSPS.
After considering the alternatives and the emission reductions
achieved, the resulting control costs, and other associated impacts,
the EPA concluded that the control requirements in Regulatory
Alternative 3 reflect the application of the best system of emission
reduction that has been adequately demonstrated.
A more stringent level of emissions limitation was not selected
because control beyond Regulatory Alternative 3 would result in costs
that are disproportionately large compared to the additional emission
reduction achieved. Regulatory Alternatives 4 and 5 were estimated to
achieve an additional emission reduction of about 2.4 thousand and 6.7
thousand Mg/yr, respectively, at an additional cost of about $6.8
million or $32.3 million for the two alternatives.
Under the proposed rule, the control requirements for new,
modified, and reconstructed SOCMI process units would apply to two sets
of wastewater streams: streams with flow rates of 1 Lpm or greater and
a volatile organic concentration of 500 ppmw or greater; and any stream
with a volatile organic concentration of 10,000 ppmw or greater
(regardless of flow rate).
2. Process Wastewater Collection System
As discussed previously, effective control of SOCMI process unit
wastewater emissions requires control from the point of generation
until treated to comply with the treatment standards, or until recycled
to a controlled process unit that is in compliance with the standards.
The proposed standards require that emissions be controlled during
wastewater collection and transport in piping or individual drain
systems and during handling and treatment in wastewater tanks,
containers, surface impoundments, and treatment devices by using
covers, lids, water seals, roofs, and enclosures designed to reduce
emissions. Proper work practices, including periodic monitoring,
inspection, and repair, are also required to ensure that the equipment
will control emissions. Emissions from these wastewater collection,
transport, and handling systems are believed to be significant, thereby
requiring the use of controls to effectively reduce air emissions.
3. Process Wastewater Treatment
The proposed regulation provides four options for demonstrating
compliance with the SOCMI process unit wastewater treatment standards:
three treatment options based on numerical emission limitations and an
equipment and design specification. Of the options based on numerical
emission limitations, the first option may be adopted by all affected
sources. The remaining options based on numerical emission limitations
may only be used by certain classes of sources, as discussed below. Any
facility may choose to use the equipment and design specification as an
alternative to the emission limitation requirements.
The first treatment process compliance option is removal of VOC
from the wastewater based on the removal efficiency of the BDT, which
is a design steam stripper (i.e., a steam stripper meeting specific
design and operational criteria). Under this equipment and design
standard option for demonstrating compliance with the process
wastewater treatment standard, if the owner or operator installs and
operates a steam stripper that meets the requirements, listed below,
the treatment unit is in compliance with the treatment process standard
of the rule. These design and operating parameters include:
(1) Minimum active column height of 5 meters;
(2) Countercurrent flow configuration with a minimum of 10 actual
trays;
(3) Minimum steam flow rate of 0.04 kilograms of steam per liter of
wastewater feed;
(4) Minimum wastewater feed temperature to the steam stripper of 95
degrees Centigrade;
(5) Maximum liquid loading of 67,100 liters per hour per square
meter; and
(6) Minimum steam quality of 2,765 kilojoules per kilogram.
The first of three additional treatment process compliance options
that are formatted as a numerical emission limitations is a requirement
for 99-percent removal of volatile organic mass from the wastewater.
The 99-percent removal may be achieved through use of steam stripping
on other control technologies. For example, another way to achieve the
99-percent removal is through air stripping.
A second treatment process compliance option that is provided for
demonstrating compliance is to treat the wastewater stream to achieve a
volatile organic concentration of 50 ppmw provided the owner or
operator demonstrate a volatile organic mass removal of 95 percent or
greater. This treatment option is provided to allow additional
flexibility for the owner in demonstrating compliance with the
wastewater treatment standard; treatment of wastewater streams to a
concentration of less than 50 ppmw generates a wastewater stream that
would require no additional control from the point at which it exits
the treatment unit. This option is limited in its applicability for the
reasons discussed in Section IV.F.3. The 50 ppmw limit was selected
based on analysis characterizing the volatile organic concentration of
wastewater streams in the SOCMI database that would be subject to the
proposed standards both before and after treatment. The limit is the
minimum concentration that characterizes the volatile organic level of
SOCMI wastewater streams treated to comply with the proposed standards
using the BDT steam stripper.
The third numerical emission limitation option for demonstrating
compliance is to remove a calculated mass of VOC from a wastewater
stream where the mass of VOC to be removed is calculated on the basis
of the annual average wastewater density and flow rate and the volatile
organic average concentration in the wastewater stream. This option is
designed to accommodate the control of combined streams for the reasons
discussed in section IV.F.3.
The proposed rule also provides an alternative treatment process
compliance option for biological treatment units; under the
alternative, an owner or operator must treat affected wastewater
streams in a biological treatment unit that destroys at least 95
percent of the organics. The EPA is allowing a 95-percent destruction
efficiency for biological treatment units as a compliance alternative
for the treatment process standards in part because the Agency believes
the use of these units will have the effect of increasing the overall
mass reduction achieved under the rule. This results from the fact that
if affected wastewater streams are allowed to be managed in a
biological treatment unit, then it is fully expected that other non-
affected wastewater streams would also be managed in these biological
treatment units, resulting in additional control achieved or streams
that may not otherwise be controlled under the regulation. The
alternative for biotreatment units in this rule is also consistent with
other regulations regarding wastewater treatment, such as the
biotreatment provisions of the HON.
4. Vent Collection for Vapor Recovery or Destruction
Volatile organic compounds are emitted from vents on enclosed or
covered process wastewater collection and treatment system devices such
as individual drain systems and steam strippers. These emissions are
required to be vented through a closed-vent system meeting the
requirements established in the rule. The closed-vent system must route
these vapors to a vapor recovery or destruction device achieving at
least a 95-percent destruction or recovery. This limitation is based on
the average efficiency of a conventional VOC recovery devices. The
option of meeting an equivalent standard (achieving an outlet
concentration of 20 ppm by volume on a dry basis corrected to 3 percent
oxygen or providing a minimum residence time and temperature) for
enclosed combustion devices is provided as well.
Because biological treatment units destroy the VOC in the
wastewater, a well-operated biological treatment unit is not required
to be covered and vented to vapor recovery and destruction. Instead,
the proposed regulation requires an owner or operator electing to use a
biological treatment unit to meet the 95 percent control requirement by
demonstrating that 95 percent of the volatile organic entering the
biological treatment unit is being destroyed and not emitted to the
atmosphere.
H. Modification and Reconstruction Considerations
Under the General Provisions for modification (40 CFR 60.14) and
reconstruction (40 CFR 60.15), facilities that are modified or
reconstructed after the date of proposal of a standard are subject to
the standard. An owner or operator of an existing facility who is
planning changes in the facility that could be considered modification
or reconstruction shall notify the appropriate EPA Regional Office 60
days prior to making the changes or commencing construction, as
applicable. The enforcement division of the appropriate EPA Regional
Office will make the final determination as to whether an existing
facility is modified or reconstructed and, as a result, subject to the
standards of performance of an affected facility.
1. Modification
Upon modification of any emission source, an existing facility
becomes an affected facility and therefore, subject to the standard.
With certain exceptions, any physical or operational change to an
existing process unit that would increase the emission rate from that
process unit of any pollutant covered by the standard would be
considered a modification within the meaning of section 111 of the Act.
If a physical or operational change to an existing process unit would
increase VOC emissions from the process unit, the owner or operator
either can take appropriate measures to offset the emission increase
within the process unit such that there is no overall net increase in
emissions from the process unit as a result of the physical or
operational change, or allow the process unit to be classified as an
affected facility under the modification criteria and control the
process unit to meet the requirements of the NSPS.
Under the current regulations, an emission increase from one
affected facility (i.e., process unit) may not be offset with a similar
emission decrease at another affected facility to avoid becoming
subject to NSPS. In addition, all emissions, not just the incremental
increase in emissions, of the pollutants that have increased from the
affected facility must be in compliance with the applicable standards.
Under the General Provisions to part 60, the following physical or
operational changes are not considered to be modifications even though
emissions may increase as a result of the change (see Sec. 60.14(e)):
1. Routine maintenance, repair, and replacement (e.g., lubrication
of mechanical equipment; replacement of pumps, motors, and piping;
cleaning of equipment);
2. An increase in production rate without a capital expenditure (as
defined in Sec. 60.2);
3. An increase in the hours of operation;
4. Use of an alternative fuel or raw material if, prior to proposal
of the standard, the existing facility was designed to accommodate that
alternative fuel or raw material;
5. The addition or use of any system or device whose primary
function is to reduce air pollutants, except when an emission control
system is replaced by a system determined by the EPA to be less
environmentally beneficial; and
6. Relocation or change in ownership of the existing facility.
The following discussion identifies some possible changes to
process unit operations used in SOCMI that might be considered
modifications. The magnitude of the industry covered and the complexity
of the manufacturing process permit only a general discussion of these
possible changes. Therefore, the list of potential modifications for
process units provided below is not inclusive.
a. Feedstock, Catalyst, or Reactant Substitution. Feedstock,
catalyst, or reactant substitution is dictated by economics and the
level of availability of the feedstock, catalyst, or reactant.
Depending upon the specific process, changes in feedstock or catalyst
may require substantial capital investment to modify the process to
accommodate the change. The magnitude of the capital investment may
prohibit feedstock or catalyst substitution for many chemicals.
Many of the chemicals produced in the SOCMI can be manufactured
from two or more different feedstocks. For example, cyclohexane can be
manufactured using either phenol or cyclohexanol as the feedstock. In
most cases, however, feedstock substitution would likely require both
equipment and process changes.
Substitution of reactants within the SOCMI process units is also a
likely change that could constitute a modification. For example, for
many chemicals, the potential exists to substitute air for pure oxygen
or a chemical oxidant as a reactant or vice versa. Changing to an air
oxidation process may be advantageous because: (1) Air is readily
available; and (2) expensive corrosion-resistant materials are not
required compared to the use of chemical oxidants. However, there may
be major disadvantages in changing from an oxygen or chemical oxidation
process to an air oxidation process, including a substantial reduction
in plant capacity, a large increase in the reactor-related process vent
stream flow rate (i.e., increased VOC emissions), and an altered
product mix. The use of oxygen or air oxidation may be substituted for
chemical oxidation processes as well. Reactant substitutions of this
type may increase process unit VOC emissions to the atmosphere and, as
a result, may constitute a modification (unless the fixed capital
expenditure exceeds 50 percent of the fixed capital cost required to
construct a comparable new facility, in which case it would be
considered reconstruction).
b. Process Equipment Changes. Process equipment changes also may
constitute modifications. Examples of potential modifications are
replacing a fixed-bed reactor with a fluidized-bed reactor, increasing
the plant capacity by increasing the size of the reactor or adding
additional reactors, and changing the product recovery system (e.g.,
from an absorber to a condenser). Such changes might be considered
modifications because they can result in increased VOC emissions.
Again, capital expenditures may be a factor in determining whether the
change is a modification or a reconstruction.
c. Combinations. A combination of the changes described above could
be chosen in any given situation with the decision based on the most
advantageous economics for the site-specific conditions. The
combination of changes might be considered a modification if they
resulted in an increase in emissions. The most common combinations are
plant expansions or simultaneous changes in feedstock and catalyst as
described earlier.
2. Reconstruction
An existing facility may become subject to NSPS if it is
reconstructed. Reconstruction is defined in Sec. 60.15 as the
replacement of the components of an existing facility to the extent
that: (1) The fixed capital cost of the new components exceeds 50
percent of the fixed capital cost required to construct a comparable
new facility; and (2) it is technically and economically feasible for
the facility to meet the applicable standards. Because the EPA
considers reconstructed facilities to constitute new construction
rather than modification, reconstruction determinations are made
irrespective of changes in emission rates. If the facility is
determined to be reconstructed, it must comply with all of the
provisions of the standards of performance applicable to that facility.
I. Monitoring Requirements
The proposed standards include requirements for continuous
monitoring to ensure that owners suppress and capture emissions from
the process unit wastewater collection system, treat the wastewater to
reduce the VOC concentration, and convey emission from the wastewater
collection and treatment to a control device as specified in the
regulation. The specific parameters that need to be monitored are
discussed below.
Enhanced monitoring is required for certain control device
parameters to demonstrate compliance with the standards. Failure to
maintain the established values of the monitored parameters would be an
enforceable violation of the emission limits of the standard.
1. Wastewater Collection
The standards require monitoring to ensure that the wastewater
collection system equipment, which includes tanks, surface
impoundments, containers, and drain systems, is operated with no
detectable leaks. The standards require owners or operators to monitor
initially using Method 21 to demonstrate that the system has no
detectable leaks according to the procedures in the rule. The standards
also include a requirement for semi-annual visual inspection of the
wastewater collection system to detect and repair any leaks in the
individual drain system.
2. Wastewater Treatment
The proposed regulation requires each owner or operator using a
steam stripper to comply with the design and equipment standard
specified for wastewater treatment processes to install, calibrate,
operate, and maintain according to manufacturers' specifications
continuous monitors with continuous recorders of:
(1) The mass rate of wastewater fed to the stripper;
(2) The mass rate of steam fed to the stripper; and
(3) The wastewater column feed temperature.
These parameters are either established during an initial
performance test or according to design specification in the
regulation. They are typically monitored in the industry to ensure
proper operation; therefore, ensuring continuous compliance of a steam
stripper with the specified requirements for VOC removal requires no
additional monitoring burden.
Owners or operators using a biological treatment unit to achieve a
95-percent total VOC reduction across the unit are required to measure
the volatile organic concentration in the influent and effluent on a
monthly basis and identify appropriate parameters to be monitored to
ensure continuous compliance. These parameters must be determined
during the initial performance test as demonstrated to the
Administrator's satisfaction, and monitored accordingly.
3. Enclosure and Closed-vent System Monitoring Requirements
The proposed rule establishes requirements to ensure that negative
pressure is maintained on enclosures and that emissions are routed
through a closed-vent system with no detectable leaks. If the closed-
vent system contains bypass lines, the proposed standards require the
owner or operator to ensure emissions are not bypassing the control
device.
An initial performance test must be conducted to ensure that
negative pressure is maintained on all openings of each enclosure, and
a monthly inspection must be performed to confirm that any enclosure
openings that were closed during the performance test remain closed.
To ensure continuous compliance with the requirement of no
detectable leaks from the enclosure and closed-vent system, monitoring
with a portable hydrocarbon detector is required to be performed
initially along with a program of annual visible inspections of
ductwork, piping, and connections to covers for evidence of visible
defects. If visible defects in the closed-vent system are observed,
readings greater than 500 ppm by volume above background are measured,
or enclosure openings do not have negative pressure, a first effort to
repair the closed-vent system must be made as soon as practicable and
no later than 5 calendar days after identification of the problem. The
repair must be completed no later than 15 calendar days after
identification.
To ensure the control device is not being bypassed if bypass lines
are present, owners or operators must install, calibrate, maintain, and
operate according to manufacturer's instructions a flow indicator that
provides a record of emission point gas stream flow at least once every
15 minutes. As an alternative, the proposed rule allows bypass lines to
be sealed in the closed position and visually inspected to ensure they
are being maintained in the closed position. The use of flow indicators
or seals on the bypass lines ensures that process vent streams are
continuously being routed to the control device.
4. Control Device Monitoring
The purpose of enhanced monitoring is to provide a means for major
sources to demonstrate that the affected facility is in continuous
compliance with the standards. In light of these requirements, the EPA
has considered how sources subject to the NSPS would demonstrate
continuous compliance with standards for SOCMI process unit wastewater.
The EPA considered three monitoring options for control devices:
(1) the use of continuous emission monitors (CEMS) to measure total
VOC; (2) the use of CEMS for surrogate compounds such as total
hydrocarbons (THC) as surrogate for total VOC; or (3) the continuous
monitoring of control device operating parameters.
The first two options were determined to be unreasonable for this
industry as discussed below. Although continuous emission monitors for
total VOC are currently available, these devices are not universally
applicable within this source category. Current emission monitoring
systems that measure VOC emissions operate by flame ionization
detection (FID), photoionization detection (PID), non-dispersive
infrared (NDIR) absorption, or other detection principles that respond
to VOC levels. However, in most cases, VOC monitors provide only a
measure of the relative concentration level of a mixture of organics,
rather than quantification of the organic species present. This trait
necessitates the use of VOC CEMS more as a relative indicator rather
than as a conventional emission monitor. Cases where it is possible to
consider the VOC monitor as a conventional CEMS are, for the most part,
limited to instances where only one organic species is present or where
equal incremental amounts of each of the organic species present
generate equal instrument responses. These instances are very unlikely
to occur at SOCMI process units.
In addition, a CEMS system that uses gas chromatography to measure
gaseous organic compound emissions may not be suitable for applications
where the number of VOC compounds to be monitored exceeds five. (See
proposed Performance Specifications 101 and 102, appendix A of 40 CFR
part 64, October 22, 1993 at 58 FR 54648.) However, SOCMI wastewaters
can be expected routinely to have multiple chemical constituents with
variable concentrations. Under these conditions, implementation of a
CEMS system would be a costly undertaking. Furthermore, parametric
monitoring has been demonstrated to be an effective means of indicating
continuous compliance. Therefore, because a CEMS requirement would
place an extra burden on the industry without increasing the accuracy
of compliance demonstrations, the first two options were determined to
be unreasonable. Owners or operators using control devices (e.g.,
incinerators or condensers) to comply with the proposed standards may
use CEMS where applicable to demonstrate continuous compliance.
However, parameter monitoring is also allowed if control devices are
used. The Agency has selected temperature as the operating parameter
that would then be monitored to determine ongoing compliance with the
standard. For example, owners or operators of incinerators would have
to monitor the combustion temperature (or the temperature before and
after the catalyst bed if a catalytic incinerator is used), and owners
or operators of condensers would have to monitor the temperature of the
vapor exhaust stream.
The use of CEMS on control devices is not proposed to be required
for the following reasons:
(1) CEMS cannot accurately determine compliance for many SOCMI
wastewaters;
(2) For each of these control systems a measurable control device
parameter (e.g., temperature) is considered to provide a suitable
indication of performance for determining compliance; and
(3) Temperature monitors are considerably less costly than CEMS.
The proposed standards, therefore, would be based on parameter
monitoring to demonstrate compliance with the standards for control
devices. The Agency is soliciting comments on the selection of
temperature as a parameter to monitor for compliance and any available
data on the correlation of the control device parameter to the control
efficiency. The proposed rule would not preclude owners or operators
who are using control devices to comply with the rule from choosing to
use CEMS to demonstrate compliance.
The continuous monitoring of control device operating parameters,
established during the performance test or specified through design, is
used to determine whether continuous compliance is achieved. Failure to
maintain the established values for these parameters would be an
enforceable violation of the emission limits of the proposed standards.
Some of the process parameters are already monitored as part of normal
operation. Therefore, continuous compliance is assured without imposing
an additional unnecessary burden on the facility.
In the proposed rule, enhanced monitoring is only applicable to
control devices used to meet the requirements of the regulation.
However, the EPA fully intends to make this rule consistent with other
enhanced monitoring requirements. Therefore, the EPA is soliciting
comments on the extent the enhanced monitoring requirements in the
proposed rule are sufficient to meet the overall requirements of the
Agency with regard to enhanced monitoring under section 114(a) of the
CAAA or are additional requirements needed within the rule to meet the
requirements of the CAAA.
J. Performance Test Methods
Test methods and procedures are required to ensure compliance with
the proposed standards, which include requirements for demonstrating
that an emission point or process unit wastewater stream does not
require control or that it is in compliance with the control
requirements. Requirements to test for no detectable leaks from control
devices, enclosure and closed-vent systems, and process wastewater
collection and treatment systems are also included.
1. Wastewater Concentration and Flow Determination
The standards require the use of approved test methods and
procedures to ensure consistent and verifiable results for
demonstration that a wastewater stream does not require control, or for
demonstration that the allowed emission levels are achieved when
controls are applied. Affected wastewater streams are subject to the
standards if they meet either of the following conditions at the point
of generation:
(1) The average flow rate of the affected wastewater stream is 1.0
Lpm or greater and the mass-weighted average volatile organic
concentration is 500 ppmw or greater; or
(2) The mass-weighted average volatile organic concentration of the
affected wastewater stream is 10,000 ppmw or greater, regardless of the
stream flow rate.
Two important parameters must be quantified to determine whether an
affected stream must be controlled. These parameters are the annual
wastewater quantity for a stream and the volatile organic concentration
of the stream at the point of generation.
Several methods can be used to determine wastewater quantity. These
methods include using knowledge about the capacity of the wastewater-
generating process or the waste management unit, and using measurements
that are representative of maximum annual wastewater generation rates.
Knowledge-based methods are allowed to provide flexibility and to
provide less expensive alternatives than actual annual measurement if
the appropriate information is available.
For quantifying the volatile organic concentration of the
wastewater streams, three methods are available: (1) Knowledge of the
wastewater streams; (2) bench scale or pilot scale test data; or (3)
physical measurements of volatile organic concentration. These methods
have been allowed to provide flexibility and to provide less expensive
alternatives than actual measurement if the appropriate information is
available.
If the actual volatile organic concentration of the wastewater
stream is determined through direct measurement, the regulation
specifies that the procedures of Method 25D in appendix A of part 60,
``Determination of the Volatile Organic Concentration of Waste
Samples,'' which provides a relative measure of the emissions potential
of the stream, be used to analyze the sample. Alternatively, the sample
may be analyzed to determine the volatile organic concentration using
any test method or test data that has been validated according to the
protocols in Method 301 in appendix A of part 63. As pointed out in
section II of this document, there are several issues associated with
the use of method 25D on which the EPA is soliciting comment.
Flow rates may be determined using information about the maximum
annual production capacity of the process unit, knowledge of the
process, and mass balance information or by measuring the flow rate at
the point of generation during conditions that are representative of
average wastewater generation rates.
2. Performance Tests
The initial performance test requirements of section 60.8 of the
part 60 General Provisions are not required for treatment processes or
vent stream control devices. Instead, the proposed standards provide
alternative means of compliance that the EPA considers equivalent to
the direct measurement of emissions as required under Sec. 60.8 and
less burdensome to the industry.
The proposed rule includes treatment process performance test
procedures for the effluent concentration, percent reduction, and
required mass removal standards. These test procedures involve
measurements of volatile organic concentrations using Method 25D or any
other methods for which the results are validated using Method 301.
Performance testing is to be conducted at representative inlet flow
rates and at volatile organic concentrations under which it would be
most difficult to determine compliance.
For noncombustion treatment processes complying with the percent
reduction requirement, the total volatile organic mass flow rate
entering the treatment process and exiting the treatment process shall
be determined by computing the product of the average flow rate of the
wastewater stream entering or exiting the treatment process and the
average total volatile organic concentration of the entering or exiting
wastewater streams, respectively. The flow rate of the entering and
exiting wastewater streams shall be determined using the inlet and
outlet flow meters, respectively.
For combustion treatment processes complying with the percent
reduction requirement, the total volatile organic mass flow rate
entering the combustion unit shall be determined by computing the
product of the average flow rate of the wastewater stream entering the
combustion unit, as determined by the inlet flow meter, and the average
total volatile organic concentration in the waste stream entering the
combustion device. The volume exhausted shall be determined using
Method 2, 2A, 2C, or 2D of 40 CFR part 60, appendix A, as appropriate.
The average total organic concentration in the exhaust downstream of
the combustion unit shall be determined using Method 18 of appendix A
of part 60, or any other test method validated according to the
procedures in Method 301 of appendix A of part 63.
A performance test to demonstrate compliance of a vent stream
control device with the organic compound reduction efficiency
requirement shall use Method 1 or 1A of 40 CFR part 60, appendix A, as
appropriate, to select sampling sites. The mass flow rate of organics
entering and exiting the control device shall be determined by using
Method 2, 2A, 2C, or 2D of appendix A of part 60, as appropriate, to
determine the volume exhausted and by using Method 18 of appendix A of
part 60, or any other test method validated according to the procedures
in Method 301 of appendix A of part 63, to determine total organic
concentration.
A performance test to demonstrate compliance with the mass removal
provision shall consist of a determination of mass removal required to
be achieved and a determination of mass removal actually achieved. The
total required mass removal is calculated by adding together the
required mass removal for each individual affected stream to be
combined for treatment. The required mass removal for each affected
wastewater stream prior to combination of the streams for treatment
shall be determined using the wastewater average flow rate and volatile
organic average concentration at the point of generation for each
affected wastewater stream to be combined for treatment. The actual
total volatile organic mass removal in the wastewater stream shall be
determined using the same procedures as described for noncombustion
treatment processes complying with the percent reduction requirement.
Finally, a performance test to demonstrate compliance of a
biological treatment process with the 95-percent mass reduction
requirement must be conducted using the procedures specified in the
proposed rule. The control efficiency of the biological treatment unit
is a function of the fraction biodegraded in a properly operated
biological treatment unit. This fraction shall be determined using the
procedures in appendix C of 40 CFR part 63.
A performance test is not specified for the design steam stripper;
installation of the specified equipment, along with monitoring to show
attainment of the specified operating parameter levels, demonstrates
compliance with the equipment design and operation provisions.
Each vapor collection system, closed-vent system, fixed roof,
cover, or enclosure must be evaluated initially and at annual intervals
using Method 21 of appendix A of part 60 to determine the presence of
detectable emissions from leaks. Method 21 represents the best
available method for detecting leaks from these sources.
K. Reporting and Recordkeeping Requirements
The reporting requirements necessitated by the proposed standard
are authorized by section 114 of the Act. In addition to the reporting
and recordkeeping requirements specified in the part 60 General
Provisions, the proposed standard would require the submittal of
several types of reports. First, the part 60 General Provisions would
require notification reports, which inform the Agency of facilities
subject to the NSPS. These reports include notification of
construction, anticipated and actual startup dates, and physical or
operational changes. In addition to the information required by the
General Provisions, owners or operators would be required to provide
information with the notice of construction identifying the process
unit and stream as well as a brief description of the intended
treatment and/or control technology. As part of the notification of
startup, sources would also be required to provide more detailed
information on the waste stream and waste management units. For
example, sources would provide information on the chemical
manufacturing processes that are subject to the proposed rule,
information on the intended compliance strategy, and any required
control device parameter ranges, unless the parameter ranges have
already been established in the operating permit.
Reports of the required design analysis (for steam strippers) or of
performance test results of emission control systems would be required
as well. These reports show whether a facility is initially meeting the
level of the standard. The proposed rule would override the General
Provisions requirements for quarterly reports for excess emissions and
monitoring systems performance. Instead, semi-annual reports would be
required in the event of each control equipment failure or instance
when monitored parameters are not within their established values. Each
semi-annual report shall include the date of the inspection,
identification of each waste management unit in which a control
equipment failure was detected, description of the failure, and
description of the nature of and date the repair was made. The semi-
annual report shall also contain information on monitoring results that
exceed the boundaries established in the operating permit.
Owners or operators are required to keep records of all reports
submitted under the proposed rule, of all monitoring parameters,
equipment inspections, and of the determination of volatile organic
concentration and/or annual average flow rate using knowledge of the
process. Records must be maintained for 5 years.
L. Solicitation of Comments
The EPA seeks full public participation in arriving at its final
decisions, and strongly encourages comments on all aspects of this
proposal from all interested parties. Whenever applicable, full
supporting data and detailed analysis should be submitted to allow the
EPA to make maximum use of the comments. The Agency invites all parties
to coordinate their data collection activities with the EPA to
facilitate mutually beneficial and cost-effective data submissions. The
EPA is interested in participating in study plans, data collection, and
documentation. Please refer to the FOR FURTHER INFORMATION section at
the beginning of this preamble for technical contacts at the EPA. All
comments should be directed to the EPA Air Docket, Docket No. A-94-32
(see ADDRESSES). Comments on this notice will be accepted to the date
specified in DATES.
In addition, the EPA particularly requests comments and data on the
following issues:
1. The proposed approach to reducing the burden on owners or
operators of waste management units, treatment processes, or control
devices that allows owners or operators to comply with the control
requirements of the proposed SOCMI NSPS for these waste management
units, treatment processes, or control devices by demonstrating
compliance with the benzene waste operations NESHAP, the HON, or the
RCRA air emission standards for hazardous waste treatment, storage, and
disposal facilities;
2. The EPA's proposed approach to identifying parameters that
define process unit wastewater streams that do not require control,
whether it is feasible to identify such streams in ways other than
through concentration or flow rate cutoffs, and information for
defining such streams;
3. The selection of temperature as a control device parameter to
monitor to demonstrate compliance with the control device standards,
and the correlation between temperature and the control efficiency,
especially for regenerable activated carbon adsorption systems; and
4. The inclusion of maintenance wastewater as part of the scope of
the proposed standards and any barriers to the control of maintenance
wastewater streams that meet the concentration and flow criteria used
to identify those streams that require control at new facilities.
5. The accessibility of SOCMI monitoring data and periodic reports
to the general public as required by section 114(c) of the CAAA.
6. The extent the enhanced monitoring requirements in the proposed
rule are sufficient to meet the general requirements of the EPA for
enhanced monitoring.
7. The appropriateness of using method 25D and the resulting
volatile organic concentration in the applicability and compliance
determinations within the structure of the proposed regulation without
discounting the non-VOC portion of the volatile organic concentration
and also without eliminating low volatility compounds from test
results.
8. The relevance of including in the NSPS an alternative percent
reduction compliance option for treatment processes that is based on
the fraction removed by the design steam stripper for the individually
speciated VOC.
Commenters wishing to submit proprietary information for
consideration should clearly distinguish such information from other
comments, and clearly label it ``Confidential Business Information.''
Submissions containing such proprietary information should be sent
directly to the contact person listed above, and not to the public
docket. 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
the submission when it is received by the EPA, it may be made available
to the public without further notice to the commenter.
V. Administrative Requirements
A. Public Hearing
A public hearing will be held, if requested, to discuss the
proposed rule in accordance with section 307(d)(5) of the Act. Persons
wishing to make an oral presentation on the proposed NSPS for SOCMI
Wastewater should contact the EPA (see FOR FURTHER INFORMATION
CONTACT). Oral presentations will be limited to 15 minutes each. Any
member of the public may file a written statement before, during, or
within 30 days after the hearing. Written statements should be
addressed to the Air Docket Section (see ADDRESSES), and should refer
to Docket No. A-94-32. A verbatim transcript of the hearing and any
written statements will be available for public inspection and copying
during normal working hours at the EPA's Air Docket Section (see
ADDRESSES).
B. Administrative Designation and Regulatory Analysis
Under Executive Order 12866 (58 FR 51735, October 4, 1993), the EPA
must determine whether a regulation is ``significant'' and therefore
subject to review by the Office of Management and Budget (OMB), and the
requirements of the Executive Order. The order defines ``significant
regulatory action'' as one that is likely to result in a rule that may:
(1) Have an annual effect on the economy of $100 million or more or
adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local, or tribal governments or
communities; (2) create a serious inconsistency or otherwise interfere
with an action taken or planned by another agency; (3) materially alter
the budgetary impact of entitlements, grants, user fees, or loan
programs or the rights and obligations of recipients thereof; or (4)
raise novel legal or policy issues arising out of legal mandates, the
President's priorities, or the principles set forth in the Executive
Order.
This action was submitted to OMB for review. Changes made in
response to OMB suggestions or recommendations are documented in the
public record.
C. Compliance With Regulatory Flexibility Act
Under section 605 of the Regulatory Flexibility Act of 1980 (5
U.S.C. 601 et seq.), federal agencies are required to assess the
economic impact of federal regulations on small entities. The Act
specifically requires the completion of a Regulatory flexibility
Analysis in those instances where small business impacts are possible.
Because the impact of the proposed rule on all entities is likely to be
insignificant in terms of changes in industry output, changes in
expansion plans, and employment loss, it is reasonable to conclude that
small entities, regardless of their number, are not significantly
affected. Therefore, because these standards impose no adverse economic
impacts, a Regulatory Flexibility Analysis has not been conducted.
Pursuant to the provisions of 5 U.S.C. 605(b), I hereby certify
that this rule, if promulgated, will not have a significant economic
impact on a substantial number of small entities.
D. Paperwork Reduction Act
The information collection requirements for this proposed rule have
been submitted for approval to the Office of Management and Budget
(OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. An
Information Collection Request (ICR) document has been prepared by the
EPA (ICR No. 1697.01), and a copy may be obtained from Sandy Farmer,
Information Policy Branch (2136), U.S. Environmental Protection Agency,
401 M Street, SW., Washington, DC 20460, or by calling (202) 260-2740.
The public recordkeeping and reporting annual burden for this
collection of information is estimated to average 13 hours per response
for reporting and 203 hours per respondent for recordkeeping. These
estimates include time for reviewing instructions, searching existing
data sources, gathering and maintaining the data needed, and completing
and reviewing the collection of information.
Send comments regarding the burden estimate or any other aspect of
this collection of information, including suggestions for reducing this
burden, to Chief, Information Policy Branch (2136), U.S. Environmental
Protection Agency, 401 M Street, SW.; Washington, DC 20460; and to the
Office of Information and Regulatory Affairs, Office of Management and
Budget, Washington, DC 20503, marked ``Attention: Desk Officer for
EPA.'' Responses to any OMB or public comments on the information
collection requirements contained in this proposal will accompany the
final rule.
List of Subjects in 40 CFR Part 60
Environmental protection, Air pollution control, Reporting and
recordkeeping requirements, Volatile organic compounds.
Statutory Authority: The statutory authority for this proposal
is provided by sections 101, 111, 114, 116, and 301 of the Clean Air
Act, as amended; 42. U.S.C., 7401, 7411, 7414, 7416, and 7601.
Dated: August 31, 1994.
Jonathan Z. Cannon,
Acting Administrator.
[FR Doc. 94-22133 Filed 9-9-94; 8:45 am]
BILLING CODE 6560-50-P
